1. $10k prize pool. Maybe I'm thinking too small here. If this one goes over well again, just double the pool for the third iteration.
2. marketing budget yes, please. Make it one proposal (prize pool + marketing). The whole thing has a marketing element to it. I don't see a reason to split it up.
3. 3 winners: $6k for first place, $3k for second, $1k for third.
4. 1 phase, 2 weeks

EDIT: what rishi said: payout in HIVE