You mentioned there are multiple parcels, is this just a coincidence or historically are similar parcels available? 

This is a no-brainer to me, and the others have already mentioned it.

If so you may have some full doc options which have the best rates typically and terms.Like others have mentioned you have DSCR loans too but this only allows you to purchase non owner occupied properties (not primary residence or second home occupancy type properties).

As @Robin Smith mentioned, for assessing demand I used FurnishedFinder.com/stats; you can see demand data for a given city and some pricing data too.

A small correction on @Brian Burke mentioned about the centralized location, while there's no one place, there're actually multiple places, that offer view and feedback on a variety of syndicators.

So- in your approach, I would not mention that at all.

Also you mention he has an awful reputation yet you acknowledged in your initial post you repeatedly buy properties his brokerage represents...not quite adding up.

I'm taking everything you mentioned into consideration.  

I once ran across a hot tub where the customer mentioned it tingled when they were getting in it .

Do a series with each focused on the different things you mentioned.