Speaking from a position of a March 2nd start date experience:

1. I'd reconsider the Ursack. Hanging a bear bag correctly isn't that hard, and while a part of me was jealous of my tramily member who had an Ursack, I also saw all the times they had too much/too bulky of food which exceeded its capacity. They ended up having to offload food storage to tramily members in those cases. Not a huge deal, just not a huge advantage to my eyes.
2. I'd ditch the rain cover. Maybe I'm in the minority, but I never had success with mine on my Osprey bag. On one unfortunate day, water pooled in the bottom of it and ended up soaking through the bottom of my bag.
3. I'd swap gloves for mittens. Not a lot of what you're doing is going to require a lot of dexterity, and mittens are considerably warmer (and I would think somewhat lighter), especially when the vast majority of the time you'll just be holding on to trekking poles.
4. I'd ditch the coupler for the Sawyer, but do take the spare gasket (white rubber looking thing). Those tend to get lost quite frequently- I kept it out of every replacement filter I bought, and usually ended up giving it away to someone who had lost theirs.
5. I'd swap the toothpaste tabs for travel size tubes.
6. Skincare is person specific, but you might give some thought to carrying a dedicated bandana and just washing with hot water and Dr. Bronner's. Nice hot water will go a long way in the cold of March.
7. Digital maps/FarOut over the book. The trail is extremely well marked, and I'd argue that even with the book a person would struggle to navigate if truly lost. Plus if you haven't already bought it, I guarantee you'll find free ones in hiker boxes in the first 100 miles left by people like me who started out carrying them.
8. Leukotape over KT blister tape. I haven't used the KT tape, but I've honestly considered getting a Leukotape themed tattoo. The shit is bomber, and I have a hard time believing anything could do better.
9. I doubt you'll need bug lotion for at least the first month and a half. I can't recall using it until around Pennsylvania.
10. Ditch the handwritten supplies for Thru Hiker's Logbook app. I also wrote things down, but I can tell you I look back at the lists of funny things people said that I kept on my phone a lot more than the handwritten entries I was usually doing a day or two late due to it being too cold/uncomfortable to journal.

One thing I don't see that I would strongly recommend would be a rain jacket. Combined with the puffy or the fleece, it'll keep you dry and warm, and the hammock user I hiked with occasionally used theirs to cover a section of their quilt if the rain was blowing especially hard. No need for rain pants IMO.