Is it possible to use an ERC token contract on the Binance chain? Would you just replace the uniswap router for the pancakeswap router? Or is it more complicated than that?
ERC20 and BEP20 are not fully interchangeable. BEP20 has some extra stuff, if I remember right, so you'll need to add those.
Also, a token typically has no idea about DEX routers - that logic should be in another contract which simply utilizes the token. Token code should be kept very minimal and simple.