If humankind follows along with the whole hero quests and recruiting, any way we can finally get some custom hero's that we create and maybe can set up with our own pictures as an avatar? Would be cool if i could make myself a leader of humankind.

I don't think heroes are likely to appear in Humankind. There will be generals, but I don't think there are specific named generals, just a limit to how many armies you can have with proper leadership. It wasn't too hard to make a mod with a custom portrait in ES2, so you can probably do that if there is anywhere in the game to put your portrait.

It was confirmed a while ago that there would be no heroes/great people in the base game. That said, every civilization is represented by a custom avatar, so you can very much recreate yourself to lead your civilization.