My experiences are a little different - I haven't studied medicine (yet), but I spent a year abroad at Trinity College in Dublin, Ireland which also has a wonderful reputation in medicine. Half the people I met among the med students were American or Canadian, with very diverse experiences. My friends there chose to study medicine there, and didn't apply just because they didn't get accepted in North America. I think actually more Australians or New Zealanders study there for that reason. So, I don't think there's contempt from Irish students for non-Irish medical students. In studying at Trinity, you get 3 degrees in medicine & obstetrics & surgery in their 6 year course (Americans with suitable bachelor's degrees enter in year 2, so 5 yr. program). Now, Trinity also has the reputation of being rather "posh," but the students are very accepting people and among student age, are very tolerant of people from other racial or sexual orientations. I'm considering going back to Trinity for med. school (also contemplating UK and Australia)
I'd be lying if I didn't say there are some situations where being of a certain race is uncomfortable. I'm Asian-American and frequently got weird or curious looks and questions. Funnily enough, most of that came from foreigners (Germans, French). But once they realized I could probably speak English just fine and probably better than a lot of them, they became accepting instantaneously. You have to keep in mind that Dublin has only become cosmopolitan in the last 5 years, and the people are still adjusting to influxes of different cultures. Their growth has been remarkable.
I also had a Canadian "friend" at the Royal College of Surgeons. If anything, she turned out to be more of a close-minded jerk than any of the Irish.
While drinking is a huge part of their society, I don't think it's correct to say you're in the wrong place if you don't drink. Plenty of Irish people even don't drink, and they're slagged, but you can't be forced to drink. And, there's plenty of fun to be had without drinking. some of my friends took religious vows not to drink, and a lot of my time was spent on drinking bans for athletic reasons (although when the bans were lifted, we went wild and had a fab time). Just saying that drinking ANYWHERE is not a prerequisite to having loads of fun.