MY wife and I aren't some sort of big time multi family real estate agents, but we have done a deal or two a year and have had some success just starting simple (we started by house hacking a duplex), and have incrementally increased our projects. 

Payment of x for first 3 year then increase to z yrs 4-8.The possibilities are literally infinite.

Will this area see a huge increase in value and rental income?

Well, the standard tactic is to use a skip tracing service to find a property owner's phone number.

I actually increased my original offer by 10k, and PinPoint accepted my offer today.

A bird dog looking to meet your requirements and standards!

As for vacation spots, easiest way to increase attraction is getting creative with designs, especially with paint and get GOOD photos with professional cameras.

In general more bedrooms and bathrooms increases value, but then again, it's not always as simple as that.

I don't recommend this approach as standard operating procedure, but in that deal, my first, I was somehow able to walk away with a $30K profit.

Speaking from experience in the real estate sector, I'm increasingly inclined toward a diversified strategy - 25-75% REI to be broad.