After talking with an attorney on if repair was responsibility of lower residence or my residence, knowing it was builder's fault but would be difficult/useless to try to get them to fix it 15 years later, we fixed the retaining wall for $9K. 

@Robert Cheek Thanks for the response.

Thanks ahead of time for your responses ( if any) :)When pricing a multi family property ( for the sake of this question ... a 2-4 door ) how much if any markup should there be on a property that is fully occupied?

We got a call that day from him saying he has an offer, and he wrote up an agreement with a 3% commission supposedly paid by buyer *yet I have to sign this commission that seller is responsible.  

It is not considered routine lawn care and should fall under your responsibilities.

And yes, that makes you responsible for those other costs. 

@Harjeet Bhatti Thank you for the response. 

Thanks for quick response, Maria!

Thank you for your response Neal.

I thought I had a line on a property manager but I am not happy with the responses I am getting so I am continuing to look.