Most likely I will repeat a lot of things other posters have already said, but I will give you nevertheless my complete feedback. I did the JMT last year and this year during the last week of July and the first week of August. Although the conditions were vastly different in regard to snow on the passes and creek levels at crossings, the overall conditions on the JMT were very similar. Both years I had only two days with rain/hail. Both years the temperatures at night went only once below freezing. That gives you a good impression of what to prepare for.
I missing on your list several items: Hat, sun glasses, lip balm, sunscreen, headnet, DEET, maps, whistle, bear canister, camera, fire starter, fuel bottle.
Items where you could save weight are rainjacket (Dry Ducks are only $15 and you get the pants for "free" with the jacket), head lamp (Photon Micro is sufficient light in camp), ground cloth (for example the GG polycryo), stakes, bowl, Nalgenes (get either Platypus or free gatorade bottles).
One item where you could save a lot of weight - but for a lot of money - is the sleeping bag. I was both years fine in my WM Summerlite (had to put on my down jacket during two nights below 30F). At 19 oz it saves you almost a full pound.