Basically you want to do lots of trips, starting with overnighters and progressing on to longer trips and discover what works for you. I would recommend a 1.3 oz sil tarp (8x10) for shelter, a lightweight sleeping bag (Feathered Friends is one good brand) and a small sleeping pad, together with a smaller cook set - My light weight cookset is a one liter lightweight aluminum ( not titanium). I have sometimes carried alcohold stoves, but I currently prefer a MSR Pocket Rocket with usually an 8 oz canister. Per BTU produced, I believe this will beat an alcohol stove.

I wouldn't worry about "losing your pack" unless you will be crossing a lot of really hairy streams. Basically your pack is your PSK, and everything in it is carefully selected for versatility.

You did not say if you will be doing this trip with a companion - good friend is a real handy ultralite accessory. I believe Mr and Mrs Jardine share a double bag, the stove, tarp, etc. so each of them is effectively carrying one half of your big 4.

I am not into long trail hiking, but essentially you are stringing together a series of 5 to 7 day hikes, with resupply at known points along a well used trail (at least for the AT).

I would carry much less cutlery. Jardine carries a SAK Classic, used to open his care packages at resupply points. Otherwise he never has to cut anything, or so he says. You need a Leatherman as your supply of do-dads increases, especially ski bindings, elaborate stoves, etc. As things simplify, the L tool is less necessary.

You may be able to do with less of a FAK. Your headlamp, bandanna, etc. can be particularly good FAK components, even if carried separately.

It is all about finding what will work for you. There are quite a few ultra enthusiasts with websites that have some good information, but test it all yourself.