I like to take a warm, but light, enough jacket so I don't have to bring any extra layers. It also compliments the sleeping bag so that can be lighter as well.
A 7 ounce top and 6 ounce bottom will not worm you up nearly as much a a 13 ounce down jacket will.
As long as the jacket and bag are warm enough, you can save huge on leaving clothing at home.
I also almost never take any 1st aid equipment or a knife. I have never been in any situation that either would have any use. There is honestly enough crap that you have that you can use to stop bleeding or make a splint.
I guess if I was in the desert with nothing around, I would have a 1st aid kit.
Most of my gear is long pants and long sleeve that I wear, a long sleeve shirt if wearing the short sleeve is a must, a jacket, sleeping bag and usually just an 1/8" pad.
I always find soft ground to sleep on and a 3" pad is sooo overrated.
All of this not even trying and the pack usually weight in at less than 4 pounds. The rest of the little things can add up too though.