1. I'll do both. If it's a video game character I'd have to go with Nathan Drake from the Uncharted series. I feel like having Drake as a roomie would just bring treasure hunting adventure. Plus, he could teach me all that crazy parkour shit he does as well as how to be a badass with a gun. As for an anime character, I'd go with Yukihira Soma from Shokugeki no Soma. Cuz like, bruh, he can cook anything to perfection. Like. Anything. Plus, discounts at his restaurant and he's a pretty chill dude. I'd never have to worry about having a bad meal again though, and that's the most important part.
2. I would pull that lever, and if I'm lucky 3 people are on that rail!
3. It depends on the type of apocalypse. Are we talking zombies, or something more along the lines of Fallout? If it's zombies I'd probably just find a secure area for shelter first, and then after I find a decent weapon(preferably something that would last a while like a sword or a baseball bat) go ham on killing zombies! I'd basically want to become the Negan of our world(I'd look that dude up unless you had plans to watch The Walking Dead). But if it's like Fallout I'd probably just wander about until I found a community I liked and stay there until I died, and explore the wasteland whenever I felt like it.
4. A little of both, actually. The important things I decide. Things such as where I work, where I live, where my money goes, etc. But I'm also easy to pushover which is why if my friends want to do something I don't, I usually do it anyway because I don't want to be the person that upsets someone.