My view is there are some good investments and some marginal ones but they seemingly have a decent track record of paying off.

You are definitely on the right track with deals. 

Track everything you are responsible for and review that regularly and it might help you decrease expenses and increase the income.  

There are paid groups you can join that are run by someone who charges you but keeps things on track. 

@Charlie Ryan, I am a bit confused by your specified numbers, so I want to make sure I am tracking exactly what you are saying so please chime back in if I am missing something below.You have a property worth 430K. 

I suggest looking at the proven, long term track record of each school

It's a good thing to have an inside track!

If you complete enough sales to cover their risk (insurance etc) and administration overhead, you could probably stay there a long time. 

Best of luck though man, you are certainly on the right track.

Please feel free to reach out if there is anything that I might be able to help with.It sounds like you're on the right track with your research, and I'd recommend that you keep reading, listening, and learning.