although I jumped in not know that they would try and cash my deposit check having a very good understand of principles, law and finance is paramount to success.  

Does anyone on this thread have recommendations for good cleaners who service South Side (Washington Heights)?

They got all necessary permits/approvals, etc. and House looks structurally sound and pretty good. 

I work a lot with Beau Matlock who owns The Matlock Group in Indy but good to build Networks!

All great answers above, just wanted to add that your tax guy should be able to help here I'm not so sure going to an expensive real estate attorney for an LLC alone is a good use of funds in many cases its overkill.  

Does anyone have experience legalizing prior no-permitted additions in SF and can advise if this is a good or terrible idea?

It doesn't happen overnight, but with persistence, wise investing, good money practices, good due diligence practices it can be done over time. 

Personally I wouldn't do anything without good insurance on my properties.I will say that the insurance that VRBO and AirBNB provides isn't insurance.

Good luck with your decision, and feel free to ask more questions!

But this is exactly what a good lender will do - recognize this issue, understand a viable pathway forward, and then fight for it internally and externally.