1) Depends on the costs of the tiers. Overall I'm not very interested in physical goods (particularly with international shipping) but I'm also generally not willing to spend $10-25 for one digital reward either.
2) Most interested to least interested: Roxas, Thrace, Kadan, Iandir, Aiden.
3) So I'm torn about this. On the one hand, a lot of the comments have really liked the art/backgrounds of the game and I get the importance of a unified aesthetic to a game. On the other hand, given the history of crowdfunded VNs, I would be very, VERY leery of backing a one from a first-time dev that had a stated dev cycle of 5 years. A lot can happen in 5 years and I'm just not sure that I'd trust the project would finish (sorry for the guild by association but bad faith players tend to ruin the game for everyone). If it really is the backgrounds that would hold up the dev cycle, I'd be more inclined to back if there was a deliverable sooner that maybe had placeholder backgrounds. Like if you could get the script, sprites, and programming done and release at least the story for all the routes at once, then finish them with updates as the backgrounds come in.