Hona Is there a way to require setting a password upon signing up with a social?
No that's not an option. At the Flarum level, password is automatically not offered as a field when a social login is used.
Hona Some things like changing your email etc require confirming your password which you won't have set this way
The official solution to this is using the password reset feature to define a password.
Hona You should also be able to link socials (one or more) as an after thought no?
Hona there should be a way to choose to display them on your profile
Those two things are actually the same issue. Right now there's not really any "linking" going on. When you login with social, it just compares the email then discards any other information.
There is some work being done in Flarum to connect and maintain list of oauth connections, but it's still a work in progress. We will likely not try to implement this separately in FoF OAuth. We're waiting for Flarum's official solution for connected accounts.
I believe there's a different extension that exists where users can add social links to their profile (without connecting through them)