All great reminders, so I thought I'd add some extra backpacking recommendations!
First Aid - When going ultralight, my first aid consists of a couple sterile alcohol wipes, 2-3 bandaids, ibuprofen, 1-2 small packets of antibiotic ointment, and ducktape (wrapped around poles), and a small ammount of paper tape which I like for covering hot spots if I get one on my feet. Carry a small knife - you probably don't need that half-lb multi tool!
Sun protection - Check out Columbia's UL shirts. Good sun protection and super breathable. roll on sunscreen is nice to keep your hands clean as well.
Hydration - Don't get super fancy. It's easy to save weight by just using something as simple as a smartwater bottle. Nalgenes are cool for walking around town, but save the weight when you're backpacking. I also love cnoc water containers if you need the extra capacity for a dry area.
Food - Certainly true you need to replace salts lost through sweat, but don't go overboard on salty snacks. In the end over consuming is bad as well - find your recommended daily amount and make sure you're getting potassium - yay dried fruits.