hi silentkitten,
1. No, it does not. But if it's a serious injury, you'll need to declare it during medical or whenever appropriate.
2. If you are asking if having a PPL with SYFC gives you an advantage, my answer would be that I do not think so. However, it does show your interest in aviation, which is good in a way.
3. I suggest you find some work to do, not necessary something in the aviation field. Perhaps save some money within this 1+ years because if you do get into the cadet-ship program, your income will be minimal.
Good Luck!