First of all, please ditch those iodine tabs! They don't kill all the nasties (especially cryptosporidium) and they can cause severe reactions. I'm one of those who had a severe reaction (deep-seated rash which itched horribly for weeks and left permanent scars), and I wouldn't wish that on my worst enemy! Instead, pick up some chlorine dioxide tabs (Katadyn MicroPur or AquaMira tablets). They are a lot safer and zap more of the nasties. CDC on backcountry water disinfection

OK, now for the rest:
First of all, your list would be much easier to evaluate if it were organized into systems. Check out the gear lists on the home page of this site for how to organize your list. For starters, separate items worn or carried (such as what you wear, anything in your pockets and trekking poles) from the contents of your pack. Then organize into clothing carried, shelter/sleeping, pack, cooking/water, navigation, toilet articles, first aid/repair and the inevitable "other." Mark group items as such. Adding weights of each individual item would be a good idea; we may be able to suggest lighter alternatives.

As far as I can tell, you've done really well except for a few redundant items which you should omit or at least seriously question--here's a list of those:

Socks--how many pair? I wear one, carry one. Be sure they are wool or synthetic. You may want a third warm pair for sleeping socks (keep those with your sleeping bag). (I use down booties, my big luxury item.)

Undies--panties, wear one, carry one (this for us females). Bra, you need only one. Be sure they are quick-drying! Leave other extra clothing in the car for your trip home.

Second sleeping pad? Why? Seems unnecessary. Open cell foam (unless with a waterproof cover) soaks up water like a sponge! If you need more thickness, bring an inflatable or self-inflating pad instead of the foam.

Rather than a GPS, I'd take a map and compass (learn how to use them if you don't already). The GPS is an electronic gizmo that can malfunction or run out of batteries. If one of your party has a GPS, that should be more than sufficient. You really should have a map anyway; ask the map carrier in the party to photocopy the relevant portions of the map for each of the participants (carry in plastic bag)--this in case you get separated from the party.

Sunscreen--take only the amount you need for the trip in a small dropper bottle. 0.5 oz. instead of a 4 oz bottle!

Toothpaste--try tooth powder or baking soda (the latter is multiple use!) Again, take only the amount needed for the trip.

Bug spray--again, only take the amount needed in a small dropper bottle. Those spray cans are heavy! DEET tends to dissolve synthetic fabrics, too. Consider spraying your shirt and pants with permethrin before you go. That will keep the bugs from biting through your shirt and pants. Use repellent only on your skin. (Be sure to follow the precautions on the label!) What the US military uses, including civilian equivalents

Sleeveless shirt--the sun at high altitude is fierce and will overcome most sunscreens. You're also leaving your arms free for the mosquitoes and horseflies to munch. Take a long sleeve shirt instead. You'll need less sunscreen and less bug repellent.

Suture kit--are you a medical professional? Otherwise (per my son-in-law who is both an ER physician and a backpacker) you have no business using this! If you use it, the first thing the ER physician will do is to remove the stitches and scold you for using it. Take half a dozen butterfly bandages instead. Both my SIL and my wilderness first aid course taught me that it's better to leave the wound open (cover with gauze pad coated with a very thin layer of antibiotic ointment) so you can spot infection before it becomes serious.

Polar fleece pants--you already have 3 layers: zip-off pants, rain pants, Smartwool base layer bottoms; that should be more than sufficient to keep you warm. if you really want the fleece pants (they're heavy!), leave the base layer at home; you don't need both. I'd pick the lighter option.

Polar fleece sweatshirt--You already have: down jacket, Smartwool base layer top, long sleeve zip front midweight shirt, hiking shirt and rain jacket. The idea is to take just enough clothing so that you stay warm in the worst conditions you can expect on the trip while wearing everything at the same time. It might get down to 15*F, but it's certainly not going to be 20*F below zero! I'm a really cold person, and I definitely would ditch either the down jacket or the sweatshirt. Since the sweatshirt is heavier and the down is warmer, I'd ditch the sweatshirt. In the extremely unlikely event that it should get below zero, you still have your sleeping bag! If your list were organized as suggested above, this overkill would have jumped right out at you, a good reason for the suggested organization!

Clothespins--I never have taken any with me. I suggest a few large safety pins, which can have other uses.

Hand sanitizer/soap--you don't need both. Take only one, again decanted into a smaller bottle so you take only the amount you need. If you take soap, be sure to use/dump it at least 200 feet from any water sources!

Wallet--keep it as light as possible. I use a ziplock sandwich bag, leave the change home (or spend it on the way), take only my drivers license, auto insurance card, health insurance card, one debit card, one credit card and a few bills. I use an extra stuff sack as a purse and leave it in the car (with nothing in it). If you don't want to go that spartan, at least get one of those really lightweight nylon wallets.

Phone--Keep it turned off as much as possible and use it in airplane mode when it's on, or it will run down the battery trying (unsuccessfully) to find reception. You may get reception on top of ridges where you can see nearby inhabited valleys. If you have one of those new fancy do-everything types (such as an iPhone), you can get a gps application for it (another reason to leave the gps at home). Leave the phone charger hidden in the car; by itself it's of no value and replaceable and it's not useable on the trail.

Stove--are you cooking as a group? If so, not everybody needs one--two at most for the whole party. The same is true of the water filter.

Calamine lotion: No poison ivy where you're going! Baking soda made into a paste is great for bug bites. Burns are best left dry under gauze.

Knife--I hope it's a small one! My Leatherman Micra weighs 2 oz. Don't omit, but don't bring a big heavy one.

Rain cover--useless at keeping your pack contents dry. Use a pack liner. Garbage bags are too fragile. Go to the hardware store, get Glad or Hefty 2-mil trash compactor bags, and take one to line your pack. Make sure they aren't scented (nearly all the supermarket brand bags are scented). Check the bag daily and patch with duct tape if you find any holes. he mylar turkey roasting bags are great, too. Just don't squish them too hard (such as sitting on them) or they'll pop.

Trowel--those plastic trowels are completely useless; they won't penetrate roots or hard ground. I'd suggest a tent stake (sand/snow stake, 1 oz.) or even your trekking pole tips.

OK, now for stuff you may need to add, remembering that it's pretty hard to spot the omissions in your list as it is now, so I have undoubtedly missed something:

Cooking pot--if cooking separately, you at least need a pot in which to boil water (which will double as your cup and bowl). If cooking as a group, not needed as long as someone else is bringing a pot big enough for the group. If it's group cooking, you need something to eat and drink out of (cup and bowl)--consider the plastic Ziplock or Glad bowls.

Water container--get Platypus or Evernew which are a lot lighter and more compact (they roll up when not in use). Or rinse out a couple of 1-liter soda bottles (even if you dump the soda, a lot cheaper). How much water you need to carry depends on how frequent water sources are along the way. If they are frequent, 1 liter at a time is fine. If you're away from water most of the day, 2 liters or possibly 3 (hot day and no water sources at all). If you've already bought Nalgene bottles, ditch them; they are more than twice the weight of the above alternatives. IMHO, 3 liters carrying capacity is a good idea.

First aid--what I use the most are bandaids (didn't see any listed) and a tiny package of antibiotic ointment (didn't see that either). For blisters, "Second Skin" is great. Is anyone bringing a group first aid kit? If so, limit yours to these, a few gauze pads, maybe an Ace bandage for sprains, plus medications you list (small quantities, not the whole package).

Extra plastic bags (mostly sandwich bags) to pack out your TP and sanitary supplies (remember that being at higher altitude can throw off your cycle). You'll probably want to double bag--put the TP in a sandwich bag which you'll cumulate in a couple of quart plastic bags. Note that all garbage must go in the Ursack (Kevlar bag).

Remember that, in addition to food and garbage, stuff like bug spray, sunscreen, lip balm, lotions, hand sanitizer or soap must be stored in the Ursack at night. Another good reason for taking very small quantities. Also, double check your pack and pockets for leftover snacks before the Ursack is prepared for the night. If you spill any food on your clothing, that piece needs to go into the Ursack, too, until you can rinse it out thoroughly.

Rain mitts--with trekking poles, it's hard to keep your hands dry if it's pouring rain and cold enough to wear your gloves. A pair of plastic bags will do the job.

Repairs--with duct tape, wind several feet around a trekking pole or a bottle. Take a needle (also useful for removing slivers)--one with a big enough eye that you can use your dental floss (didn't see that either!) as thread.

Anti-diarrheal pills (such as Lotromin)--half a dozen. Should you get diarrhea (remember that you're far more likely to get it from you or your party not washing hands than from the water), you need something to slow or stop the process temporarily while you're hiking out!

Fire starting kit--matches (the waterproof/windproof matches sold by REI are marvelous) and/or small lighter; fire starter. This is one of the "Ten" Essentials. . You appear to have all the others!

If FUD means what I think it does (fear, uncertainty, doubt), leave that at home, too--it's heavier than anything else in your list! You are going to have a wonderful time out there in God's country!

Please take the time to organize your list by systems as suggested above, and come back! Let's see if we can get your total pack weight (not including what you'll be wearing, but including what you'll carry of shared gear) down to 25 lbs. at most!