1. (I'm not gonna waste this one) Everyone in the universe lives forever, life literally never gets boring, overpopulation NEVER becomes a thing and everyone is pleased with the new way of doing things. BAM! THAT'S how you wish for something impossible. Alternately, I would just make reincarnation real.
2. I would wish for a single Carls Jr. burger of my choice. I can't remember what it's called, but I used to eat them all the time in high school, and I haven't had one in years. I could buy one right now easily, but hey...Wasted wish. Besides, I feel like I'm doing pretty well with my first wish anyway.
3. I treat my body any way I want, and there will never be any health ramifications. I would basically use this to eat horrible, delicious food, while not ever sleeping. Seriously, sleeping is a huge waste of time. Though I guess that would no longer matter since everyone's immortal now. I'm pretty sure this is theoretically possible.