I then check to see if there are any local laws that limit the number of STR rentals in the municipality.

Also make sure you research any local government / municipal STR restrictions.

I had tried to set her up with free rent that she qualified for through various local charity programs for single mothers and everything but she never even completed the applications then I had to evict her.

I suggest that you try to invest locally.

Talk to the county taxing authority and a local real estate attorney/professional.

or, you just use wholesalersFor analyzing deals and doing the rehabs, there are plenty of free resources, either on BP, or other people in your local REIA. 

A local RE professional should be able to provide this information to you as well.In New York, we deal with this scenario frequently and oftentimes it does not make sense to legalize ADUs because the permit process is extremely lengthy, the cost is high (sometimes $150-300K for 1 ADU unit), and the potential increase in property valuable is not worth the risk.If you already have an approved permit/plan and can get your renovation down to $80K, you may want to consider this project if the ARV is say north of $800K.** You should also look into any potential property tax increases associated with this change.

Do you plan on investing locally?

Your local apartment owner association is a great resource for best practices for management and screening tenants.

My husband has been a realtor for over 30 years and we were always very active locally with investment properties.