Is this possible. i.e. can I transfer ETH from Binance to Metamask using BSC or I need to deposit it directly to Ethereum mainnet?
Simply when you do transfer ETH from Finance make sure you select ERC 20 net
If you use BEP 20 you will create a wrapped token not easily to handle for newbie. Just search on internet for ETH BEP 20 and WRAPPED TOKENS for more info