I'm in a Scottish Uni, have to say that the whole 'outside course' thing is really not an issue, you just pick what you want to do, there's plenty options even within your course area. As a biology student, I did 3 biology courses out of a total of 6 (astronomy, geology and german were the other 3), but I could eeasily have done 6/6
Wouldn't recommend advanced entry personally, I don't know anyone who's done it but I lived around a loooad of people on my course and that really helped. That said I've just gone into 2nd year and it's still ridiculously easy to meet new people.
If you don't want to pay the extra tuition fees, fair enough but I'd highly recommend it, since first year is the funnest year and is also ridiculously easy for someone who could do direct entry