I've not only thru hiked but done alot of extended trips in the west and southwest. Everyone has their own likes and dislikes but my answere are based on my personel prefrences and things I've seen fellow hikers use.
Gregory-good choice, I started out with an LL Bean, bought a Gregory in Damascus. Now use a Lowe Alpine, (fits my frame size better)
Tent; Consider the LL Bean lite stuff solo. Cheap, light, and a bug screen.
Bag, okey
The Stuff comes with alominum stakes, very light-I must have found a dozen stakes at camp sites along the AT.
Silk Liner- forget it, you don't need it.
Thermarest, started out with one, developed slow leak, couldn't find it. much prefer closed cel I bought to replace it.
Use your pack cover and forget the compactor bags. A good cover keeps everything in your pack dry.
alcohol stove is an excellent choice, I left my wind screen in a hiker box as unnecessary extra gear.
Two Smartwool lasted me Ga to Me and I still have them, Never backpack with smartwools without liners, I went the distance without a single blister or hot spot, without the liners I get both.
Rainjacket, get a set of FroggsToggs. I sent my goretex jacket and rainpants home. Toggs don't need treatment when washing, are much lighter and very durable, breathable, wind and waterproof and dirt cheap.
I took one pair if light fleese gloves.
One long sleeve wicking shirt is all you need, forget the silk top. Long underware bottoms are good, the wicking long sleeve is the only top you will need. No tee shirt but a short sleeve button shirt lets in air and I prefered it on hot days.
I prefer a light fleese pullover, get good quality.
I carried swim trunks as back up shorts and to wear in town while I did my laundry.
Rainpants, see FroggsToggs
Balaclava, leave it home, get a fleese hat.
crocs okey,
gaiters, don't leave home without them, when you hike in the rain they keep watter out of your boots and are great in the mud and snow you are bound to run into.
what is a greesepot? if I don't know what it is you don't need it.
A lexan spoon is all you need, (I had two)
Soda bottle my choice for fuel bottle.
Duct tape on hiking pole, way I did it.
ditto note pad
Old pepsi bottle good for water, I also had two collapasable nalgene water bags, (2 liter)
Forget the baby wipes, purill or any alcohol sanitizer works well with your bandana.
A half roll of toilet paper in a zip lock bag worked for me.
Don't need a cup, sent mine home.
Don't carry deet and sunscreen until you need them, purchase them when they become necessary. Same with lip balm,
I didn't need foot powder but it is nice.
I found a small bar of 100% Ivory soap in a zip lock more convient than Dr. Bronners or liquid camp soap.
Add a tube of hydrocortisone to first aid kit, you will get a rash from time to time.
Get a Swiss Army Knife, it does everything for the weight.
Headlamp, I have several, prefer the Tika Plus
Rope is good, light nylon best. Carry a cheap carabena to hang pack.
Use rechargeable batteries, carry two spares and charge them at hostels, A small charger weighs very little. Use in camera and headlamp,
A small camera on your backpack strap will keep your camera close at hand. Often great photo ops come up quickly and you don't want to fiddle for your camera. A whistle should also be on your pack shoulder strap. Forget the earplugs, you will be tired enough to sleep through anything or can improvise ear plugs. I carried several safety pins on my pack and used them to hold socks and underware to dry while I hiked.
Vitamins, and meds, don't leave home without them.
You need ID, cash, travelers checks, also have at least $2 in change as you may find a soda machine at a road or trail crossing and want a cold drink, Photocopy the pages of the data book and companion and mail just the pages you need for the section you are on to yourself.
You shouldn't need the compass, I sent mine home. The sun will tell you which way is north or south and that is all yoiu need to know. Just follow the blazes, If you are northbound east is right and west is left.
I love hiking poles.
A final word, if everyone hasd the same preferences Ben and Jerry would only hsve to make one flavor. What I outlined worked for me but may not work so well for you. Good luck and I hope to see you in Maine, I maintain a section of the trail here and also spend alot of time hiking on it.