Also paging @Garrett Brown the STR specialist to see if he has any insight to this area or advice on how to get to one of the top STRs in your neck of the woods. 

When you're doing your due diligence in MF just make sure they are not over leveraged and have some skin in the game.  

The potential for a loan call is higher and higher with sub to the more parties you involve if that makes sense.Trying to take down four homes sub to and then do remodels to them all, and then list them on short-term rental sites, and get full permitting and ok for not just the STR, but for your renovations and all prior renovations maybe done without a permit, while on subto, sounds like a pretty big mess to me.I would consult with a sub to specialist and prepare for the potential of having all the loans called at some point.

The property owner always loses while the arbiter has no skin in the game at all, just skimming profits off of the owner and can walk away any time they want without reprocussions. 

That is reality because the receiver of the info has no skin in the game, nothing to  hold them to the "advice".

Is it some kind of foundation specialist to start with to at least know what it is and know if there is anything reasonable that can be done, a general contractor, or is this something I just write off as seasonal shifting of the foundation that happens with some? 

As you can imagine, it drastically cuts down on the amount of water use when the tenants have skin in the game.

@Sharad BagriThese questions are best left answered by an entity specialist.

I'm not sure if a demo specialist or mason would be better. 

I want a specialist that's an expert, and not a jack of all trades and master of none.