Generally, no.
Some forked coins may have the same API, but doesn't have to.
Just google "your_coins_name developer api" to find the correct API for your coin.
ERC20 tokens are just coded contracts. You may found them on github. This depends on the developer.
Regarding commands and deamon, look here.
You don't need to run a daemon for an ERC20 token. They run ontop of the ethereum network.
You might run an ethereum daemon if necessary.
ERC20 describes rather a standard for tokens, than a protocol.