I've been asking for reimbursement without clear response from support or resolution.  

Did you get the final answer and resolution?

We have notified the current PMC of termination, and the company has agreed to work with us to come to an amicable resolution on open issues.

Since you’ve documented your efforts (extermination, snow removal), that helps your case.It may be worth speaking with a local landlord-tenant attorney sometimes just a letter from a lawyer encourages resolution.

Focus on a fair resolution going forward.

Yes, this will be an expense at the start of your partnership but the expense often pays huge dividends not only in efficient resolution of disagreement, but also in avoiding unnecessary conflict.Lastly, I'll just note that I often hear people excuse not having an LLC with a well drafted OA with something to the effect of "my partner and I have a great relationship, we don't need this".

However DO NOT wait for a resolution to settle with him.

Many agents will not want to proceed with a listing that carries a known title issue, and this can sometimes prompt a resolution or withdrawal of the listing until your claim is settled.Note: This information is for educational and informational purposes only and does not constitute legal, tax, financial, or investment advice.

So now it’s 18 months  that you’ve received no payments, spent 15K in legal fees, and are no closer to a resolution than you were 18 months ago.  

This slow resolution often frustrates tenants, and as a result, many property managers eventually drop warranty policies because they hinder fast, reliable fixes.Instead, most landlords find self-insurance to be a better approach.