Unfortunately there are a number of issues with the way you determine the winner:
You sort the participants based on "bitcoin transaction time", but Bitcoin transactions don't have timestamps. I'm guessing what you actually mean is the time at which the Bitcoin transaction was received. This time can vary from node to node, however, so there's no way to verify that you actually received the transactions in the order you claim.
Then, the winner is chosen by the sum of all hashes mod 9. This only gives you 9 possible results instead of 10, so the tenth participant has no chance of winning. Using this method (modulo) there is also a slight bias towards the earlier participants when the sum of hashes isn't a multiple of 9, meaning that players won't have an equal chance of winning the majority of the time.
The biggest issue, however, is that the last participant can choose the outcome of the game by broadcasting a Bitcoin transaction that gives the desired result.
Consequently, your game is not provably fair and can even be exploited by players.
For some ideas on how to make a lottery provably fair, take a look at the now defunct
PevPot.com, for example.
Good luck!
