Hi,
Sorry I can't be of too much help, but as a current oxbridge student I'd strongly advise against adding more studies out of your subject while at uni. Though time can be found to get some flying training done, it would probably be extremely hard to fit in time for any ground studies, certainly not during term time. The best time to do some training is during the summer holidays, which you get a nice long 3months of, but I'm assuming you'd be gone home in that time anyway.
Good luck with your interview!
Julian
