One geographer? Harsh! UC must be cutting down, apparently they threatened to do that last year.
I wrote a personal statement saying how much I wanted to go to UC, what I'd get out of it, why I'm suited to it etc. a bit like a personal statement really. I mentioned a coupleof specific courses and professors I'd like to be taught by too. The personal statement was then weeded to produce 4 candidates who were interviewed, these were then sorted into the 2 people who were going plus 2 reserves.
You won't be able to fly back at easter because the holiday is only a week long! It's the mythical 'spring break'. In my current uni accomodation you can't stay over holidays, but at some other UCs or if you get a private apartment then you can.
Module choices are very free and easy, you can pretty much do what you want as 3rd year geography has no prerequisites. However, you have to keep the people in Durham advised with what you are doing and how it helps you etc. Because I despise physical geography I've dumped it completely and am currently doing Urban geography, historcal geography and transport systems planning. However, I have a friend from KCL who's doing a mix of modules so it's perfectly easy to do either.
Don't worry, I had about a million questions before too!