Not dumb questions at all, anon  :)  Here we go with the answers:

1.  Corsets will hold up the boobies, no bra required  :)

2.  A properly made corset should not hurt to wear, breathe, or eat in. However, I do recommend wearing one and practicing, if you will, before you try to wear it for a long period of time.  And practice doing everything: sitting, standing, just do it to get use to it because it does take some getting use to.  For example, I’ve worn this one twice, to get the hang of it.  It’s going underneath my dress  :)  

Extra note:  I also recommend, maybe if you’re at a con, if there’s a booth with corsets sometimes they let you try them on, so you can see what it feels like.  Or if you have a Renaissance Festival, you can try there too.  I got this one from Corset Story and actually had to return it the first time because I got it too big.  According to a friend of mine you want to get them 2 sizes below your normal size, and after I did that it fit perfectly  ^^

So no, not stupid question at all, I had a lot of the same questions too.  I pretty much believed I would never find one because of my size but man, I was dead wrong  :)