Is there some market standard for an erc721 contract to handle a percentage fee to the NFT creator for each transfer ?
There is the ERC2981 interface. However, that is not supported by all the marketplaces. For example, OpenSea doesn't seem to integrate it, however LooksRare does (source).
Thank you, i entered a very deep rabbit hole ,and the conclusion is that still there is no uniform way to handle this across marketplaces 