Most differences will be due to location, size, or rules/availability.

In terms of your grandfather living there as long as he's not the owner having a dwelling fire/rental property insurance policy is appropriate.As @Greg Scott pointed out he should have a renters insurance policy whether or not he's actually paying rent.In terms of liability coverage, that depends on what you have to protect so there's no one-size fits all approach.

You mentioned a couple times that you had "feelings" of some sort about these people- reacting to your feelings when screening tenants is a good way to get caught up in a fair housing case.

If its near Jersey City or anywhere in Hudson and Bergen county, I have developers that buy site unseen 24/7 if in a good area, decent lot size and reasonable asking price.

Quote from @Ryan Fitzgerald: Go to NETWORK at the top of your screen and you can search for other investors and investment groups in your area.

Is there anything that should be done from a screening standpoint for these existing tenants? 

Recently I saw some decent sized laundromats that were priced in the $600-$850,000 range.

The difference in this portion of the execution can be $30k-$60k/yr more money in your pocket vs. that of our competition all other factors equal (such as the property size/location).Next, to drive costs down, I co-host (only for clients) at 15% which is 5-15% less than the large PM firms.  

However, you should factor in the legal cost of pursuing versus the size of your investment because this can be an expensive endeavor alone.

My partner and I developed a banking relation with a moderate sized Texas bank 11 years ago.