Is there a way to completely remove access of a role/user to a record if he/she is not the creator or the approver of? I can have a return user error action in a workflow but they still know it exists, it's just that they can't open/view it. Also, it seems that they can bypass it via creating custom reports or saved searches until I completely got rid of those permissions but that's not ideal.

I doubt you can do that, using workflow or script you can restrict access by throwing an error warning, but as you mention they can run saved search or reports to get info.

You can restrict the user/role to see just their record using ‘default to own’

Thanks both. Unfortunately, what drives whether a user can see or not a record is not the native/standard Employee field or its equivalent on transactions and not even the standard segments. That's why the role restrictions won't work for us. Since they won't need to create their own reports/saved searches anyway, we just decided to remove the permission to create or customize but not view/run. Plus the error message when viewing/editing a record they should not have access to