of this in life you can be assured: taxes, death and irritating family members.
it'll be hard to do, but ya gotta start training yourself to ignore what bothers you about your family. You might not live up to their expectations, but I don't think any of us do when it comes to our families because often, their ideas about us and for us greatly differ from what we've got in mind! Instead focus on meeting your reasonably set goals and concentrate on being a happier person -- your brother's successes are important, but not as important to you as finding peace and contentment in your own life.
as for your boyfriend, chances are, it probably doesn't drive him nuts when your family asks about his career. It could just be to him that they're asking straightforward questions and he's okay with that. If he's confident in himself, that kind of stuff isn't really going to bother him. And, if y'all are planning to become more serious (as in get married eventually), he's going to have to develop a kind of immunity to those things you find annoying about them.
like I said before, family will always have certain expectations of you and for you, but that doesn't mean you've got to comply because you are your own person capable of making your own judgments simply because you know what you need out of life.

best thing to do is learn how to smile and ignore -- that's what has helped me!