Risks: you can’t go wrong, so the contract should be thoroughly audited. The most secure way is to copy eosio.token contract as is, without any changes. Benefits: the users and investors will trust an immutable contract much more, especially if its checksum is the same as that of eosio.token. In this case, there’s no danger of the owner’s cheating. Technically, it was cheating from SEVEN team to take back my billion, but of course they didn’t have any other way. But if they would show the contract to anyone experienced, this wouldn’t happen at all.