1. There's a site that picks a winner daily (even though sometimes they seem to pick someone real and pay, recently the haven't paid anyone since most bitcoin addresses they choose is either new or very old and it seems more of a cheating IMO)
2,3,4. All good
My concern is, how winners would be chosen? Will it be in a completely transparent way in which a software will be used and everything will be video recorded for everyone to see if it's purely legit? If yes then you might have a chance, If no, then forget it.
I was going to choose a winner using a pseudo-random number from an array of address/names I pull out of a database. I have no access to Hardware RNG.