When I was thinner, about 150 pounds and 5'7", passing was very difficult and getting flat was next to impossible. I'm close to 200 now and don't have as much trouble. I think the extra weight helps to be honest. I wear an Underworks small. I should be in a medium, but it doesn't work for me at all. Ah well. I don't think you'll have as much trouble as you think you will. I do have issues with some of my tissue coming out by my armpits so I wear structured shirts that hide it completely.
To answer your other questions from my point of view...
1) Binding + T will probably destroy your breast tissue. Certainly destroyed mine. I don't care. I don't want nice breasts, I want them off, so I'm not sure what you mean by preferring to have nice ones if you have to have them. I guess everyone's experience is different, but I can't say I have an answer for that.
2) You can hurt yourself by binding. I messed up my back and my lung capacity is extremely low now (even though I've never smoked). As with the effects of T and binding on breasts, I don't care. I'm very dysphoric about my chest and have no choice if I want to feel like I'm living a somewhat normal life. I don't recommend binding long-term if you don't plan on ever getting surgery. I've been doing it for a few years and I'm paying for it now.
3) If you wear a sports bra under a tank top under a shirt, you might be able to look flattish. Having extra weight on your stomach and waist will help.
4) Don't know how to measure. It's been so long, I don't remember.
5) I've heard you shouldn't bind every day too. I still do, and I sleep in one of my worn-out ones that's not too tight. The only time I don't bind is when I'm in the shower. So if you take it to the extreme I do, yeah, you're going to have some problems. Just wearing a binder outside the house shouldn't be too big of a deal, even every day, but don't take my word for it. If you work full-time and you're doing it 9 or 10 hours a day, that would definitely be different from wearing it for 3 or 4 hours every day.
I hope this answers some of your questions. Binding does have some cons, but if you need one to feel comfortable, the cons shouldn't matter, IMO. Just be safe, don't make the same mistakes I made (and continue to make), especially if you're young and still growing.