1. Nope - generally prospective buyers will be seen on a first come, first served basis and given the opportunity to buy at the listed price. If you don't want to pay the listed price, they will move on to next in line.
2. Yes, as above.
3. €5000 - €10000 and usually refundable within 21 working days.
4. You'll need to talk to the agent about expected completion. However you will only be given a maximum of 4 weeks notice of closing.
5. Yes - do it as early as possible.