First of all, welcome to The Lightweight Backpacker! OK, I'll take the challenge! I started this process over 7 years ago and it's still continuing for me!

First of all, a couple of items about your list format which, for the most part, is quite good. First of all, the items you wear or carry in pockets, hands, around neck are by convention not included in your pack weight. They are part of "skin-out weight," the sum of total pack weight and everything you wear or carry, actually a more realistic number because that's what your feet, ankles and knees actually have to support. Therefore your base pack weight (everything except food, fuel, water) is really 15 lbs., 15 oz., which is squarely in the middle of "lightweight" (usually defined as 10-20 lbs. base weight, depending on who is doing the defining). It's actually a satisfactory base weight for most people, although the folks over at BPL consider it heavy. The 27-lb, 7-day gear list on the home page of this site has a 15.5 lb. base weight. "Ultralight" is usually defined as under 10 lbs. base weight (again, depending on who is defining! ). These conventions are primarily for the purpose of comparing your list with others, a good exercise--assuming the lists are for the same conditions--in finding possible weight-saving ideas.

The main item in your list format that needs revision is that you have two separate "buckets" labeled "Essentials." Normally "Essentials" would be defined as the essential survival items that go on all trips, both dayhikes and backpacks, such as here. That's pretty much what you have in this category, except they should be all together in one "bucket."

Second, it would be really helpful to know where, when and under what conditions you expect to use this list. A list suitable for Oregon's Columbia River Gorge in midsummer (high of 90, low of 55) is not going to cut it for Wyoming's Wind River Range where it can snow and get down to the mid-teens F in midsummer. With the list good for the Winds, you'll end up with heat stroke in a Midwest summer.

Okay, let me go through and hit the heavier items, concentrating mostly on those which will save half a pound or more:

Clothing worn: Ditch those 40.5 oz. boots. Consider either trail runners (what I use) or a pair of the lightweight "mid" hiking boots. They'll be far more comfortable, both because they are lighter and because they are more flexible and conform to your feet. You won't need as heavy socks and your feet will rejoice. I haven't had a blister since I ditched my boots! (I've never worn the boots since, either, even in winter.) In addition to saving about 10 oz. on your footwear (there is at least some truth to the saying that one pound on your feet equals 5 pounds on your back), you can also ditch the camp shoes because the lighter footwear will be plenty comfy in camp just by loosening the laces. Total savings about 19 oz.

Clothing in pack:
Missing: base layer (see "Sleeping" later) and second pair of socks. Socks are the only spare clothing I take, but with my feet as my only mode of transportation, I really want those--a pair of clean dry socks at night is awesome. If it's liable to be a soggy trip with little chance of drying anything (think Oregon in November), I'll take two spare pair of socks. I also like to take a pair of thin liner gloves for cold mornings.

"Essentials" (both buckets):
Ditch Nalgenes, already mentioned. 2 1-liter Gatorade or Powerade bottles are 3.2 oz. Assuming you can stand to drink the stuff, zero dollars! Savings, 9.2 oz. A 2-liter Evernew bottle is 1.5 oz. and can be flattened and rolled up when empty. A 2-liter Platypus bottle weighs slightly less (I was forever losing the Platy caps, which is why I switched to Evernew which has the caps attached to the bottle).
Water filter--Sawyer Squeeze, replacing their fragile squeeze bags with a 900 ml Evernew bottle, 3.4 oz. Savings, 12.4 oz. plus a lot of pumping! It's also a slightly better filter (0.1 micron instead of 0.2). Chemical disinfection won't be much lighter because of the wait time--you'll often have to carry extra water that's in the process of being treated.
Liquids (sunscreen, bug dope, Tecnu)--decant into tiny dropper bottles only the amount you need for a trip. Probable savings 4 oz., maybe more. I know this is only 1/4 lb., but taking only the amounts needed for the specific trip is an important weight saving principle. Do the same thing with your camp suds and any liquids in your toiletries.

Sleeping:
Pajamas--replace by lightweight base layer, far more versatile because they can be also worn under clothes for greater warmth on cold evenings and mornings (multiple-use is another important way to lighten up). Example: men's Capilene 1 L/S top and bottom, 9.1 oz. total. Savings, 10.7 oz. If you want a heavier base layer (Capilene 2), still about 8 oz. savings.
Sleeping bag--there's no cheap way around a truly lightweight sleeping bag with 800 or higher fill down. That will cost $$$, but if cared for properly it will last a lifetime. The cost per year of life will be less than a cheap bag, assuming you can manage the initial outlay. Example: Western Mountaineering Ultralight, size regular, 29 oz. Savings, 14.3 oz. If you want to go to a down quilt, you'll save a bit more (quilts are not for me; your mileage may vary).
Tent--A very few examples (stakes included): Tarptent Contrail, 24.5 oz.; Tarptent Notch, 26 oz.; Tarptent Rainbow, 32 oz (no trekking poles needed for this one); Six Moon Designs Skyscape Trekker, 26 oz. For all except the Rainbow, add 2-3 oz. for poles if you don't use trekking poles. The Notch and Skyscape Trekker are double-wall with net inner; the others are single-wall. Savings, 51.6 to 55.6 oz., subtract 2-3 oz. if you don't use trekking poles.

If money is no object, there's a list of various solo fully-enclosed shelters and shelter combinations weighing 20 oz. or less on John Abela's excellent website. Most are cuben fiber, a wonderful way to lighten your bank account!

Cooking: Stove and Fuel Bottle: Example (mine): Primus Micron Ti stove, 2.1 oz; MSR 8-ounce fuel canister full of fuel, 12 oz. (will last a week unless you do a lot of cooking). Savings, 18.2 oz., including close to a week's fuel. For short trips (a week or less) you'll save even more with an alcohol stove (it takes a bit more, by weight, of alcohol fuel to boil water, so for a long trip the heavier weight of more alcohol will even things out). In the case of alcohol, you carry the fuel in a soda bottle (not a smart idea with white gas). If you want to be really technical, the MSR canister mentioned above weighs 4 oz. empty, a better comparison with your 16 oz. fuel bottle.

We can whittle down some smaller stuff (some already mentioned by others), but I've already saved you close to 9 lbs. here. Since the only non-pack item is the boots (~10 oz.), your base weight will now be in the true ultralight category!

To that we have to add back (about 6-7 oz. total) a few missing items:
Extra pair of socks
Lightweight liner gloves (unless you like cold hands)
Compass (part of the "Ten" Essentials)
Whistle (ditto)
Waterproof liner for pack (unscented 2-mil trash compactor bag works fine and lasts several trips) (It's vital to keep your insulating items dry!)
Mini-Bic lighter, much easier for lighting stove (still take the matches, though)
Hand sanitizer or soap to clean your hands, if not already included.

Do you take a camera? If so, it should be on the list.