I'm unsure about the first part but for the second, if the enemy team doesn't bet, then you don't win anything, you just get your earnings back. Here's how to system works.
Let's say you bet 1000 credits and I bet 500 and we were the only ones that bet on Blu. Then on Red, there was a sum of 300 credits bet. Blu wins so you get 66% of the credits Red bet (200) and I get 33% of the credits (100) because that's how much of the betting capacity you took (1000/1500 = 0.66 or 66%). If no one else on the enemy team bets, you are refunded your credits as no other bet was made.
Just some clarification on this - it is not the enemy team that has to bet, but the enemy team must have a bet on it.
If I use the command !bet red 100, no matter what team I am on - it bets 100 on red winning.
If I use the command !bet blue 100, no matter what team I am on - it bets 100 on blue winning.
If both Sargent and I are on red, but he bets 100 on red and I bet 100 on blue - no one else has to bet.
Rewards are then calculated by taking the total amount bet (200 in the example above).
We then take each person that bet and calculate their bet as a percentage:
If red won then Sargent was 100% of the bet and he wins 190 (5% removed for betting fees).
So, again:
Pedro bets 300 on red winning, Sargent bets 150 on red winning, I bet 100 on blue winning.
If red wins, the amount that was bet for red winning was 450, the total pool is 523 (95% of 550, rounded up)
Pedro wins 66% (300/450) of 523 - total credits won: 234
Sargent wins 33% (150/450) of 523 - total credits won: 173
I lose 100% of 100 (my bet) - total credits lost: 100