However, what guarantees that the subsidy is going to be renewed in the next year?  

If they charge you hourly when anything goes wrong, charge you a fee for marketing and a fee for lease renewal, then the 10% appears to be for collecting each month.  

There are no other expenses except (1) the HOA/management fee paid my me of $80/mo (water, garbage, and grounds maintenance), and (2) the realtor processing fee of $200 paid upon each contract renewal.

While searching online I came across renew Indianapolis that is a land bank of a lot of the abandon houses in Indy.

Gives the opportunity to issue Notice of Non-Renewal instead of evicting.

Their Fee is $79/unit                                                                                                                 Tenant Placement Fee: None                                                                                                    Setup Fee:None                                                                                                                      Lease Renewal Fee: None                                                                                                        Maintenance Fee: NoneI just need a steady good cash flow 

Our 1 year lease is up in 2 months, and I think we will renew for another year, pay off the rest of the debt we accumulated moving here, build up a nice cash reserve, and not spend a couple thousand to move to a new place at this time.

If the problem persists than maybe you can start to build a case for eviction, or if they are on a month to month let them know that they won't be able to renew unless they remedy the issue.The bigger issue is if your tenant is actually growing pot.

One of those projects is a renewable energy company that I invested in several years ago.

There is a clause in the lease that says the agreement is renewed each week unless either party ends the arrangement in writing.