I'm hoping someone can answer some general questions or provide links to some documentation that might explain how it works. I have been trying to figure it out and it just seems like I'm missing something.
I have a basic SharePoint Document Library. I have enabled the standard Content Approval Flow options.

As far as I can tell, this simply sets the Comments and Status fields based on how a users interacts with the UI in the library.

Is there any way to set who the approver can be? Is there any way to configure Email notifications? Who can approve this, anyone with Contributor rights?
After playing around with this OOTB feature I started to look at building my own flow. I turned off the Approval on the Library option. However when I use the Set Content Approval Action I get a message that "Content moderation is not enabled on the library". I re-enabled the Content Approval Flow option and no longer get the error. However, this now enables the Approve/reject option in the SharePoint UI which can conflict and override how my custom flow it running. My Flow will generate Approval Tasks for the end user in the Flow interface but the option from the ECB menu still allows users to Approve/reject.
Is this how it really works? Am I missing some sort of configuration option, way to disable some of those menu option? The Set Content Approval Action almost seems useless if you can't disable those UI options from the Library.