Based on what you stated, the rate they are quoting you is in the ball park, as of today's rates.

Your deal rate may be low with low ball offers, but your chance of success per deal will be higher.  

IS there a ball return in the basement that goes under the foundation that could be expensive to fix?

Even if I low balled the montly rent I still come out with a nice amount on the 8 properties minus the yearly property taxes it is a no brainer.

The fourplex that I am looking at does not have electrical conditioning system, but instead evaporative coolers on all 4 units.I have not experience with this cooling system.Is it possible to bring the temperature below 80F when the outside is above 110F?

First, Rentometer is great for a ball-park figure, but it doesn't take into account a lot of information on the house (type [SF vs. duplex], square footage, condition, finishings, etc.)I would recommend reviewing rental listings on Zillow/Craigslist that are comparable to your in-laws house so you can get a better idea of what rents would be. 

If you low-ball the seller and provide little in return no one will listen.

It would be great to meet like-minded people for once (financial freedom is a foreign concept to my college peers) so at times I feel like the odd ball. 

Had an low ball offer rejected but built some rapport with her on the home.

But pretty much every HML will require PG's as well.. but if they have a mechanism to get the property back without a foreclosure then maybe they don't need it.. and frankly with the no money down borrower with limited capital the PG is kind of worthless anyway.. again just spit balling here.. but in mortgage states like OHIO were foreclosures take a long time..