I did the JMT this year and it's beautiful! I'm stoked for you to do it!
*50 ounce backpack. I liked my SMD swift a lot, I used it with a 2-panel z-rest in the pad compartment and a rolled up ridgerest. I also had the wing belt. My pack was about 21 (with the 2-panel @ 2ounces, wing belt @ 4ounces). That's a savings of 27.5! That's worth not ignoring! If I did it again I'd recommend a Gossamer Gear Gorilla. For the record I had a fair amount of extra space in my pack, and will have even more so with regular use (aka no bear can). You can look into getting like a zblast or something cuben and light as heck, I think they'd work well if your other stuff was minimalistic enough to have enough volume. Next time I'll actively try to work at making that option work. I like having a gorilla sized pack (smd swift is relative sized) for trips with my girlfriend where we share gear (I carry most of it).
Mini bic-s are light and awesome, EXTREMELY reliable. Firesteel is heavy. You also have matches. Do you NEED 3 fire starters? nix 1
Look into your first aid kit. 4oz is a lot. I'd try to trim to about 1-2oz. In essence look at things, figure out what injury you're both likely to have, and able to fix. I took something for HEAVY blood loss, some tape (multi-use!), bandaids, and a few others. If I need to sanitize my denatured alcohol can do that. If I need to wrap a wound I have an extra shirt. If I need a splint I can use a tree branch.
Repair kit. Include razor blade (who needs a knife? I used to bring one and never used it for something a razor blade can't do. drop over 3 ounces), a needle, and an entire thing of floss for thread. Seam sealer is good, so is super glue.
Sleeping pad: Make sure this is comfy to sleep on. Some people can, some people can't. I'll trim labels off things... but I will bring a 2.5" inflatable every time. I don't sleep well without it, period.
Sawyer Filter: Honestly a lot of the time I didn't even filter. What I would recommend is re-packing some aquamira drops (Not tabs! they take forever). So what you wind up with is like 1 ounce or less for your whole trip. Check out Mike Clellands book on lightweight backpacking for this, or read the section using google (google the book title and "aquamira")
I'd switch to a 2liter platypus. Weight wise it's not much different. Why I'd do this is because at the end of the night I want : water for drinking that night. water for cooking. water for washing. water for morning oatmeal. water for morning drinking. water to start the next day with.
Camp shoes are nice. I missed them because I didn't bring them. Rock on!
Nice homemade alc stove!
35ounces is a fair amount for sleep (haven net + tarp). The bug protection is nice depending on season. I'm bringing something with a bug net next time. If you're going late season you might not need the tent. I went with a bivy + poncho tarp. 15 ounces for rain gear & shelter! It was spartan as hell. I'd go with something else next time, but if you want to this is a spot you CAN drop weight.
Headlamp. Petzyl e-lite is 1oz. It sucks for night hiking, is fine for around camp + camp chores at night. I thought it was worth the tradeoff. They are prone to getting sand in them making them harder to turn, eh, whatever. save 2.some ounces
I'd nix the emergency tinder.
Try a gatoraide water bottle, I liked this WAY more than a smartwater bottle, a bit heavier. Part of why I like this is a: some little side streams are so small that a shorter water bottle can fit under them when long bottles can't. b: The wide mouth makes filling it easier. c: it feels better in my hands & I can rely on the grooves instead of having to grip it.
do bring: plenty of fun snacks. Nutella + tortillas. I got REAL sick of candy bars. Check out powdered hummus, it's the cat's pajamas. I also took bread bags x 2 for my feet when I had to put on wet socks for short periods of time. Your camp shoes might not need them (bonus!)
Do: have a good attitude & plenty of "this isn't so bad!". I slept miserably every night. I had a lot of migrating aches and pains. I ripped my shoes (both of them) and repaired them on the daily with floss. I had MTR lose HALF my resupply bucket. I kept going and had a blast. I ran into a chap with a rubbing pack headed home. I offered to fix his issue. I offered to swap him packs (he was at his start, I was at my end). He refused and went home. Don't be him.
A sleep shirt. This is pure luxury. ULers would suggest nixing them. I didn't bring one. While I wouldn't say this is must have kit.... I in the future will be looking for a uber lightweight shirt to sleep in. It's SO NICE having clean clothes on. Actually there's another recommend, wash you clothes decently often, it will brighten your outlook. A perfect time to do so is when stopping for lunch.
If you need any help of advice please feel free to message me. I got so much good advice on these forums I feel it's my pleasure to repay the favor.