Can I change them anywhere? Like provide my MEW for the payout?
I believe if you keep TAAS on exchanges you wont be receiving the dividends,similar like Iconomi. You need to have a wallet for which you own the private keys like MEW or mist to receive your payout
By the way the payout will be in ETH or BTC, can anyone confirm this?
This is not true. We are educating exchanges on the process of distributing payouts. It is done in ETH. MEW is supported.
my question should be clarified ..
where can I provide MEW adress to get my dividends / payout and TAAs sent to?
You don't. This is the beauty of a smart contract that knows where to send the funds.