The tenants cover most expenses so there is minimal room to create operating efficiency, and the likelihood of materially pushing rents is probably low. 

Some operations were offering free housing, so they could bill for the testing.  

I would try to contact a RE trainer in the state. everyone has to get their RE training from someone and the top RE trainer in that state will know whose good and whose bad.

I got a 15k lesson in that one this last year and two other BP members got even more expensive lessons with this one frequent BP poster  :)  I can laugh because 15k is not going to change my life.. but other investors this could be serious Its why I am in the 1% of  BP frequent posters ( and it could be far less than 1%) that think that paid training is one of the best ways to actually get going in this business as opposed to thinking you can listen to a few pod cast read a few blogs read BP until your eyes bug out and your all of a sudden going to be a successful RE investor...

I heard that you can donate a house to a local fire department for a training.

What areas of Indiana are you going to operate in?

Point #3 as mentioned is less passive then #1 & #2 it will come down to your confidence in your operators ability to execute.If you decide to take on #4 this will take quite a bit of your time.

I will be running the operation out of my real estate office, so no need to budget for overhead there.

There are also individual training sessions on a variety of topics.

I get paid fairly well, $90,000+ annual salary but I'm just exhausted with the hours, nights, weekends and holidays and stress from daily operations.