-you need to warn people to use Bitcoin at the start page not somewhere else in details
-site almost gives the impression you can buy multiple tickets with one payment
-it doesn't really say HOW you are using random.org -Unless you provide details about how you are picking the winner you look like other lottery scam sites - as it is now, you could pick anyone to win, even yourself, and no one would know if you followed the rules or not
-using random.org is ok but unless others can get the same random data as you, it's not useful. You could just redo it until you get what works for you.