I finally had time to look through your list. Some items are a little vague. I hope you've looked at the gear lists and other references I gave you. They are good models for organizing your own and for organizing your gear.

Shelter:
Tent--Quarter Dome probably a good one to start with. Return the footprint. They are strictly a salesperson's gimmick. I never use one. If you insist on having something under your tent floor, get a thin plastic painters dropcloth and cut a piece to fit (make it a couple inches smaller each side). This will work fine for snow, where you probably do want a ground cloth.

Sleeping:
Sleeping bag: What Balzaccom said! Check out sleeping systems on the Mark Verber site I gave you earlier for possibilities. Be sure you have a warm enough pad! The NeoAir is rated to 32* so gets quite cold below freezing. The BA insulated air pad will probably take you down to the mid 20s. You'll want a fairly thick closed cell foam (CCF) pad on top for supplemental insulation for a total R value of at least 5 for cold weather camping. Try the pads on the floor at home for a night or two to be sure you can sleep comfortably on them. Pillow--I use my pack or a stuff sack and stuff inside the clothing I'm not wearing inside the sleeping bag. There are also lightweight inflatable pillows. Silk liner adds no warmth to a bag, maybe 1-2* at most--anything more is advertising hype. When I used one, it took me forever to untangle myself in the morning, so after a few days I ditched it. It most certainly won't turn a summer bag into a winter bag. Look at the Mark Verber website I referred you to for ideas. Forget the emergency bivy--fine for dayhikes but you will already have your shelter and sleeping gear with you when backpacking. If you use it to extend a summer sleeping bag, it will become a sauna inside.

Pack--try to get a supportive, comfortable pack that weighs less than 4 lbs. Other things (such as comfort) being equal, closer to 3 lbs. is better. Wait until last to get it so you know it will hold and support the gear that you will put into it!

Tools--take the smallest possible knife. Mine weighs less than an ounce. Ditch the trowel and use a tent stake (what I use) or even just your boot heel and a stick.

Hydration system:
Nalgenes--ditch; they are several times the weight of a Platypus or even a recycled Aquafina or soda or Gatorade bottle. Steripen--I couldn't work the thing. It has a reputation for being tempermental in cold weather. If you're snow camping, you'll have to melt snow for water anyway, so you might as well boil. Otherwise use chlorine dioxide tablets. Sigg bottles (if that's what "Sigg" refers to) are far too heavy.

Cooking--How are you cooking? Pot? Stove? A spoon is sufficient as an eating utensil.

Ditch the camp seats. A small sit pad (now there's a use for that blue foam pad; cut it into 2 or 3 equal parts) is sufficient.

Hygiene--one small microfiber towel per person is plenty. Or buy a package of Handi-Wipes at the supermarket--that's what I use. Lighter and dry lots faster. If you're using soap, use tiny amounts and be really careful to rinse at least 200 feet from any water source--soap (even biodegradable) kills aquatic life. Get some of those tiny dropper bottles from GossamerGear.com and decant just enough soap for the trip. The same for any other liquids (toiletries) that you take.

Clothing is where people tend to overload. I take the same clothing in winter as in summer except for an additional layer or two in winter. My outer layer (rain jacket and pants) is the same both winter and summer. That not only keeps the cost down (mostly the same clothing for all seasons) but lets you regulate your body temperature more efficiently. It's really important not to get sweaty while you're moving (you need to keep your clothing, especially your insulation layers, dry at all times) and not to get chilled when you stop, so you'll be taking layers off when moving and putting more on when stopping multiple times during the day (what I call the onion principle). Read the Mark Verber article on clothing for more information about layering. I take enough layers that if I wear everything all at one time I will be comfortable in the worst possible conditions. The only "spares" I take are extra socks.

I hope this gives you more ideas. Read the articles I suggested. Especially read up on winter camping (articles on this forum's home page and posts in the winter section). Get out on short trips--preferably car-camping with your backpacking gear, so you can bail out to the car heater if things go wrong--until you have more experience. Then go to camping no more than a mile or two from the trailhead, again so you can bail out easily if necessary.

Good luck, and feel free to ask more questions once you've read those articles! (There's no such thing as a stupid question; the only stupidity is not asking it!)