Well, I can't tell you exactly what classes are like (ask me in a few months!), but I might be able to help with the other things.
Any majors are open to hearing students, technically. The idea behind the HUG program was to let in hearing students who wanted to work in a deaf-related field. So one could major in, say, English, but it probably wouldn't be viewed favorably unless that person was planning on teaching English to deaf kids. So majors like interpreting and education are really popular for the hearing kids. Personally, I'm doing psychology as a minor, since I currently work as an interpreter in a treatment facility and would like to do something related when I leave. I'm undecided on my major, but it's between education and deaf studies. I've time.
Interactions: I hear a lot of bitching about whether or not Gally is open to non-DEAF (you get what I mean by the capitalization?), non-ASL using students, whether they're hard-of-hearing, implanted, mainstream, whatever. I think the majority of it depends on the attitude of the person in question. I'm going to Gallaudet knowing some pretty popular students on campus (with both faculty and students), so I have a good foot in the door because they already know me and my personality. The people who have problems are the ones who go in there with egos the size of Texas, with holier-than-thou attitudes. If you're laid back and open-minded, most people aren't going to give you much crap.
The only major gripe I've heard about the HUG students is regarding the ones who don't sign well or who speak without signing. I've personally witnessed hearing students walking across campus to class, chatting away with other hearing students and not signing. In those situations, yeah, deaf people get pissed, but I do too because it's just rude.
