When I click the "bitcoin accepted here" button on top, it says "Bitcoin payout amount 4.8 X your bet amount", but what does it mean? There is a bet with only 2 possible outcomes ("Yes = 1 No = 0 The FED will raise interest rates again before March 31, 2016.?") and it can't be so good that I will get 4.8x for the first one.
4.8 = 480% of your bet amount
yes 1 no 0 = 50% probability answer is correct
Wait, so someone can bet 0.01 btc for "yes" and bet another 0.01 btc for "no", and he will get 0.048 btc back for sure? TBH, it doesn't make any sense at all.
No, obviously no, you can not bet against your self, your questions make no sense.
Say if someone makes a bet on "yes" using one bitcoin address and one proxy, and then makes a second bet on "no" using another bitcoin address and a new proxy, how are you going to tell that the two bets come from the same person? I am afraid you cannot.
And even if no one does that, if roughly half of the bets are on "yes" and on "no", your site is going to take a huge loss no matter what FED does, don't you see that as a problem?