The lot is outside of the city limits (just barely) so I'm only familiar with city zoning regulations, not county or state regulations.

At a bare minimum, I'd have a T-12 and rent roll for the property, together with your current property analysis, future cash flow projection, and an exit strategy or two.

Will landlords who are barely profitable as it is sell?

It's not quite the same as bare land vs hotel.

From direct ACH, last place I thought of checking.I was suspicious though half way, but couldn't find any proof that I was charged $99 every month in his membership area, nor was there a cancel button, and there was barely any content in that area, so I thought I wasn't charged, further maybe I wasn't even a member, and stopped researching. 

I’m aware I should’ve backed out when the inspection was done but thinking I could bare the cost - it’s not sustainable for the goals I have with this property.

I need to put HVAC in the building (at least the bare minimum) and I need to repair the roof. 

And if/when dig deeper, come to find that entity is barely making a net profit end of day.

Will mail be delivered even if A and B are not officially registered with the USPS?

Luckily great tenants who caused zero issues and barely needed to sweep & mop the place before sale.