University course

You don't need a creative writing degree but it certainly isn't going hurt your chances and you'll develop a lot as a writer if you're surrounded by other writers for three years. I've applied for English literature and creative writing at UEA, University of Birmingham and University of Manchester (and to other courses elsewhere) and I'm honestly having second thoughts about being a writer, but as long as you have a degree from a good university it doesn't really matter what it's in, so if you're worried about changing your mind about working in that industry, don't. Also, a lot of creative writing courses are really competitive - only 1 in 10 applicants get given a place at Manchester - so getting onto they're definitely not a degree to be frowned at.

If not, have you considered doing your BA in English literature and then doing creative writing at postgraduate level? The MA at UEA is especially prestigious - Ian McEwan and Kazuo Ishiguro (who won the Nobel prize in literature!) are both alumni.

I think its definitely worth applying and deciding later - there's no harm in doing so. If you apply to other courses as well having creative writing in your personal statement just shows you are passionate about literature and have subject-related interests (assuming you're applying to an literature-based subject). I also have an offer from University of Edinburgh for Scandinavian Studies and English Literature even though my personal statement was centred around creative writing.

It's ultimately up to to make your degree work for you/get you places. I would argue it's the prestige of the university/course you choose that would set you apart/hold you back rather than the subject you choose to study.