Hey no problem,
I think I can answer some of your questions, but not all.
As far as the atmosphere around the school/area. . .I work at the Oklahoma Medical Research Foundation, which is on campus - about a block from the dental school. My fiance' and my roommate both work or go to school on campus as well, so I spend a lot of time around campus eating, hanging out, etc, and I see a lot of the student life (at least on campus). I also have a few friends in dental school, med school, and Ph.D. programs. The feel I get is that the dental school is one of the closest-knit groups on campus. I hear there is great comraderie (spelling?) within the dental school, both between students and faculty. The atmosphere of the campus is what you might expect from Oklahoma, very laid back and friendly. The schooling is very demanding, just like anywhere else, but the atmosphere is great here.
I've lived in Oklahoma City for about 2 years, and it's a great place to live. It's probably about the cheapest place in the country as far as housing goes. I rent a 1300 sq. ft. house in a pretty nice area about 10 mins from campus for $600/mo. I've got a garage and a fenced in back-yard. The city itself is pretty nice - again, laid back and friendly. You could argue that there isn't all that much to do, but I feel like any place is what you make of it. There's a pretty good downtown area - lots of bars and places to hang out. It's kind of a meat-market if you ask me, but its still fun to go down there.
I would say the school is much more clinically oriented than research. That doesn't mean you can't do research here. Because it's a health sciences center, there is plenty of opportunity to do research within any of the deptartments on campus. I think most people who come here want a more clinical experience, so finding research opportunities during your schooling here isn't very hard, at least from what I hear.
I'm afraid I can't answer your other 2 questions concerning board scores and specializing. I know OU offers most but not all specialty programs within the metro area, and I cannot remember which ones are offered here and which ones aren't - but you can go other places to do whatver dental specialty you want. I'm sure that information could be found on the website, but the site doesn't seem to be working. It looks like they are trying to re-do the site and haven't got most of it up. Here's the site
http://dentistry.ouhsc.edu/, but good luck finding much of anything on it at this time.
One more thing - the dental school building was built in the shape of a molar, if that helps sway you any. It's a bit odd, actually - but it does look like a big tooth. I just hope they let me in to the molar this year.
I hope I've helped answer some of your questions. Let me know if you have any more.