Can you purchase FL resident passes for everyone in your group even if some are not residents?

No, you have to prove that your party is a FL resident somehow. There're other type of annual passes for non-residents.

Methinks not. Unless they have mail from a Florida residence or even p.o. box, a lease agreement, utility bill, something that ties them to a Florida address

Seriously... that would be a big NO.

No...they have to be a resident with proof.

You must be a Florida resident to have a Florida resident pass

No

You can purchase AMERICAS PASSES

No. Florida resident passes and tickets must be (and be able to show) Florida resident status.

No, they will check your drivers license.

No you have to have proof of residency