What manual actions are needed to maintain the site? And how often do they need to be done? (send prizes, check payments...)
In millionsbtc.com everything is automated except from the winning payouts because we wanted to make manual checks when there was a winner: i.e. check that the winner's bet was fully legit ( check its bet's payment in the blockchain, etc).
All the other things are fully automated (two draws a week included). You would not have to do anything except from marketing (if you want) and a manual transaction when there is a winner.