If you buy a property based on rents you *could* get by year 2 or 3 that not a smart choice IMO.

Since I have mortgages on both, I had not choice but to pay.

I think it is quite possible that it would dehumidify a larger area but for the walls, but ofcourse who knows for sure.I have no idea on the install price because we got the house when an aunt died and she had it done way back right after hurricane Irene flooded the whole basement, but there wasn't a choice on pro install because a hole had to be cut into the foundation as there was no window, I have a feeling if a venting spot existed it would be a pretty easy diy project.

The choice is yours.

If they do accept what's offered, it's by their choice and its in line with what their analysis says is their highest and best recovery amount.

It's hard to screw up a single family purchase, but as you expand your portfolio the financing choices you make now and along the way matter.  

They do not have much choice now, growth has to come from somewhere?

I’m thinking about providing a cleaning service and lawn care service with no choice, to ensure the property stays up to par.

Window unit-I suggest you give him a choice selecting 1 from two units of similar price range, Ask him to pick one and put new one there.

But again, that's an aesthetic and budget choice.