I had TAF when I was in college and had it in a house with a few room mates for a while.
We had a ton of fun drinking beer and playing it, pre-gaming if you will, and then we would go out and mingle with the ladies and have a few more beers. Many times we would bring girls back to the house, for choir practice and early breakfast, of course, and while some of us would hang out in the living room watching movies and whatever else the imagination can conjure, there would undoubtedly be a few folks playing the machine in the game room.
Make sure it has good beer seals, and it will be fine. I never covered the one I had with a towel or anything, but people never really put drinks or bottles on the glass anyways because they would slide off because of the slant. It never got trashed, but then again, it wasn't in a "public" place. Our pool table, on the other hand, had countless drinks spilled on it.
I'd chalk it up to the type of boy you have; playing pinball is certainly a social activity. College is a social place, a very social place really, if you want it to be. If the intent is to let the guys have a good time and socialize, it'll do just that.
I'm not sure what you want for the boy, or what kind of person he is, but you'd be surprised, shocked even, at the intrigue elicited of asking a co-ed, "Want to come back to my place and play some pinball?" in an actual college environment, especially if it's a rural campus or there really isn't all that much to do. It's innocence and innuendo all in one.
I say go for it. At a time and a place in most young people's lives where being an individual is very important, I would almost guarantee he'd be the only guy with a pinball machine. The "college experience" comes down to the person. I wouldn't give up my experiences in school for anything, albeit being 15-20 years ago, which now seems like eons ago.
Go with an interesting theme: Tee'd Off, NBAFB, TPZ, The Getaway, Austin Powers, all fit the non-old man, cheap, "non-offensive", non-childish, fun themes I can think of.
Good luck to him and you!