whether AQUA also have a bounty?
There will be some bounties available for bigger projects. They will be announced this weekend.
The remaining AQUA will be only available for bounties, right?
Or is there any other airdrop?
There are no more airdrops or free giveaways of any kind. The rest of the available coins are designated for tasks that will advance AQUA's development. This is an extensive list that will be released this weekend.