The difficulty is that the only comps in the same neighborhood over the past few years have been foreclosures & short sales.

Perhaps this is a bit naive, but are there any legal or financing concerns with using a private loan from friends/family for the down payment of an investment property (SEC regulations, underwriting difficulties, etc.)? 

I'm really impressed by the gross income considering how remote it is and difficulty accessing it in winter.  

You will have difficulty finding anyone to purchase unless the land itself has development potential.

driving returns down for your investor and making your job more difficult.  I

If your properties are not in areas where people want to live they will be extremely difficult to rent and, of course, once you do rent them you may have difficulty collecting further rent.

They may well say that's fine, especially given the difficulty of installing a larger one. 

Have you had a lot of difficulty finding good tenants that won't destroy the property?

What are some difficulties to grow your rental property portfolio?

I thought about forming a separate one for the properties I would like to purchase however, how difficult is it to obtain financing if I do that?