No. USCIS could revoke visas, but courts could review those revocations. Seems courts will now have less authority to review.....just my interpretation.
By law, every person who applies for a B2 visa is already assumed to have intent to stay in the US. Having a US GF is a very strong tie to the US. It is always up to the applicant to overcome that suspicion of immigrant intent. I wish you good luck.
You MUST provide the numbers for all 3 years if the sponsor was required to file taxes those years. Otherwise, you must provide the reason the sponsor was not required to file a tax return.