If Bounty of the Luxa somehow has multiple flood counters on it, you'll still get only {C}{G}{U} when you remove them all.

If Bounty of the Luxa leaves the battlefield while its triggered ability is on the stack, you can't remove any flood counters from it, even if it had one before it left the battlefield. You won't put one on it as the ability resolves, but you will draw a card.