How to get tokens after bounty? Will they be sent to the platform wallet?
No, you will immediately receive them at your wallet address, which you specify when registering a campaign participant. Check that it should be a erc20 wallet
Can I use browser wallet as a metamask?
It is not prohibited if it is compatible with the format. And of course, if you are sure that the funds are safe. After all, browser wallets in my opinion easier to hack.