I had a feeling it was a scam to get the rent reduced for that month. 

If you increase your amortization to 40 you reduce your pay down and increase your interest rate.

But that person would have to be on the loan in order for the experience to count.I usually encourage partnering with an experienced investor for the first few deals in order to learn and reduce your risk by minimizing "newbie" mistakes. 

I think you can learn from this experience and reduce the likelyhood of it occurring again.  

What advice do you have for securing one's rehab project in Baltimore city (i.e reducing or preventing the incidence of theft or break-ins)?

With buying a house you are out mortgage, taxes and insurance.. only benefiting from principalWith an investment even at a 10% return will reduce your monthly rent significantly and should be out of pocket much less than monthly home ownership expenses..Mortgage you are committed long term not renting..I laid this down for my friend yesterday..

Are there any mentors or opportunities to shadow deals?

Your window of time for making money in STR is going to be reduced depending on where you invest.

Or should I ReDuce the Rental fee Eliminate the PM?

If you are confident in your numbers and know the range of return on investment, your risk will be reduced.