with half a trillion bitcoins, I'm pretty sure people would be a helluva lot more competitive than with a trillion dollar prize. IOI doesn't stand a chance . And yes, definitely participating!
Most debit cards can be used in online transactions, but you might want to check with your bank first! I once had one which can't be used. Regarding security, some debit cards now offer virtual cards. You can allocate some of your money to your virtual card and avoid using your real debit card for online transactions!
To mend things with lots of people. I have made lots of enemies in the past, dealt with them in the wrong way, and I just wish I could tell past me to be less immature and self-centered.