Jacs88:
1. Might as well try, I've seen lots of short flighties!
2. No they don't mind, as long as you tell them, and if you're successful you just provide them with the new certificate as soon as you can.
3. Don't ever wear any nail polish to an interview!! Or jewellery!! (Wearing a watch is a good idea though - nothing too blingy or trashy)
4. No one ever knows what they're looking for. My personal opinion is not to attract too much attention to yourself, but don't stay a quite little mouse either. Just be yourself!
5. Casuals don't get any benefits, but the higher hourly rate makes up for it. In saying that, you can have busy months and quiet months! Everyone seems to survive though.