But whatever you do. Pick to your strengths don't pick something for the challenge of it you wont thank yourself. Cross interest with subjects you'll perform in and you'll be fine is the best thing I could say
No, but there is a practical examination where students have to sing and/or play an instrument. So if you don't play an instrument you would have to be able to sing 6 songs very well as be able to sight-sing. :)
Hope this helps.