I now have two people with multiple properties who are will to talk to me about my buying their properties.

It's likely that there's multiple layers of paint on the exterior and it's only seeing the top layer of paint. 

It has been my experience that students will flake out on signed leases but not signed leases AND skin in the game (i.e. money).

My game plan would be find a buyer whose willing to do $10,0000 down, $650 a month (maybe someone with bad a credit or wont qualify for a bank loan?).

I am currently in the process of educating myself about the REI game while i finish up my business degree.

I would recommend using FHA to get into the game as an OO property and then using that to snowball into more properties down the road.

What is the best strategy to apply for multiple loans with minimizing impact on credit score.

It could be a lot easier to get 1 loan rather than 6 mortgages and you get the added benefit of having to pay expenses and management on only a single property rather than multiple spread across a wide area.

I don't see any major issues with your strategy, but flipping is always a risk, and you should always have multiple exit strategies in mind. 

Have multiple exit and operating strategies.Stress test and run worst case scenarios.