I'm definitely aware of the tax implications (that's why I mentioned it in my OP :-) ).I already have a couple of other businesses (one successful for over a decade, one a startup), and I'm adept in several fields (including long-term rentals as well as flipping).

Its a whole other job, and you must be a systems and ops guy.

OP spending $10K on an AC doesn't make her $10K poorer.

In the past eight years and after reading thousands of market crash posts, I have seen one post where the OP stated what they were doing about it. 

The OP it appears opened his account for this particular post.

I also know that in the 6 units complex where I own a townhome they have a limit of 2 rentals as they were told by a lender doing a refi that that they wouldn’t be able to lend if a 3rd unit became a rental. (50%) OP: I would ask the specific lender(s) that you plan to apply with if they have a 51% owner occupied rule before going through all the legwork. 

My OP asks if you know of any ways for a buyer to finance besides a land loan or cash.

It's a common provision.My take is, this was aimed at co-ops and was a strategy to increase the number of properties available for rent and/or prevent the reduction thereof which would also have an impact on the cost of rent.  

OP, I'd dig your heels in, go with whom you trust, no reason to go with the escrow officer that purchased avocado toast at your realtor's last sales meeting.

I'm aware that NYC is tough on running airbnb's and that co-op's are tough to work with.