I'm wanting to keep everyone's posts in their profile in the postbit but I'm wanting to add more custom fields. How do I remove the other details in everyone's postbit and only have the posts and custom fields? Is this possible, if so how?
Have you tried just editing the template (either postbit or postbit_legacy) and removing the stuff you don't want? Custom fields do not show up unless you add them to the template or you have a plugin to add them.
The postbit is a template in the Style Manager > find style > edit templates. You would remove anything you don't want from there. I'd suggest trying it out on your test site first so you know it works.