He wants to keep most of my deposit, deducting for items that were in poor condition when I moved in and only returning 15% of the deposit to me.

Since you are saying that the property is in good condition, maybe you can do without the MC for a few years?  

Either a probation condition or an existing no contact order.   

@Dominick Galinis two major reasons, actually:1 - the best properties to BRRRR may not be eligible for conventional financing due to their condition.  

We STR owners need to stress to everyone - neighbors/City Govt/Etc that STRs are (almost) always in perfect condition.

Is the higher rent based on a refurbed unit or its present condition?

In addition you want to know what condition your high cost repair items are in.  

The rents are way under market so I decided to send non-renewal letters with almost 60 days notice and offer a lease of my own explaining the current rental market conditions, and current going-rate prices.

Now, on the other hand, if the tenant is lying and the home is in excellent condition and you have the COC then yes, you can hire a lawyer and take other actions. 

I am not sure what condition the buildings are in though.