To join the bounty signature, you should have an account with the rank of Jr. Member is the lowest. With campaigns that accept the newbie you share, most of them are potentially unlucky and potential scam campaigns. It is advisable to invest time to upgrade your rankings on the forum then consider joining signature bounty.
I fully agree with you. That not all companies with a minimum rank can reach the sale of tokens on the exchange. Many of them are scammers. You'll just waste time. You better look for trusted and proven bounty managers and try to participate in their companies.