I’m not familiar with the specific rules of 12 steps. Would joining via phone or internet violate a 12 step standard? If not, you can probably find one outside of your area, but either way keep in mind that religion/religious discussion will probably come up.
As for your questions:
In order for the other members of the group to discuss you, they would be opening up about their own attendance, which IMO makes it less likely to happen.
Whether the potential negative outweighs the potential positive is a decision that needs to be made between you and your therapist and anyone else who knows the situation in more detail.
From whatever you’ve posted here, you seem to be an intelligent, mature person and dedicated to growth. Hatzlacha in making the right decision and reaching your goal, whatever you decide.