...there was also no mention of them being Federation members in "11001001" otherwise there would have been no need for them to steal a Federation starship, they would have probably had a Galaxy-class of their own.
That doesn't follow. The city of Cincinnati is a member of the United States, but that doesn't mean City Council has its own aircraft carrier at its disposal. You're making the common mistake of confusing the Federation, a multi-state government, with Starfleet, the military organization that serves that government. Federation member worlds no doubt have thousands of starships, but they're civilian vessels. Galaxy
-class starships are Starfleet vessels, not available for public use, and there were only 4-6 of them in service at the time of "11001001" anyway.
It would be more accurate to say that if Bynaus had been a UFP member, they could've requested
that the Council assign a Galaxy
-class starship to their needs.