-what if the best answer changes ? do both people get payed ?
Best answer would not change. The best answer is chosen at the time from of the question being asked.
-what if people create fake accounts ?
Have people send an amount of Bitcoin or Litecoin to the forum's wallet to verify their account. Make it too expensive to create fake/spam accounts.
what about dealing with transactions ?
What about it, specifically?
would ltt pay for answers, or the op ?
Well, I'm not sure what's best. Another option would be to have subscriptions. Subscriptions services could be the income.
if op pays, how do you know he will pay ?
We can use multi-sig transactions. Were there are multiple private keys created for a bitcoin address. Say there are 3 private keys created... you would need 2 of the 3 to send the money.... So 1 private key goes to the forum, one goes to the OP, one is sent to the person who provides the best answer.
Person with the best answer then inputs the private key he was given into a payout field box on the forum... inputting this key will release the funds.
OP can also hold a key... if OP doesn't received and answer in a decided amount of time, then he can input his key and release the funds back to him.
what if there is no answers ?
If OP were to pay for an answer, they could take their money back via multi-sig I described above.