Let them know that there will be routine quality control checks/inspections so that if your third party inspector finds any issues with quality, the GC will be responsible for paying for the correction.These are just some theories that I think will help and plan to implement when I operate out of state flips.

If you are buying your first (or second or third) mortgaged property you do not have a whole lot to lose going either direction. 

Quote from @Eli Ling: thank you, what do you think of this email:I understand your concern about the ceiling leak and your assumption that it might be coming from my apartment.Since we both want to resolve this issue, I suggest contacting the HOA to involve a neutral third party who can determine the actual source of the leak.

Most serious and qualified tenants are searching on the major 3rd party platforms you mentioned + realtor.com, redfin, and a few others.Apartments.com & homes.com are owned by the same company and may offer some additional marketing options.Another strategy to consider here is social media - video marketing.

However, splitting the cost as Jeff suggested may get things fixed up quickly and keep the peace between both parties.

Most syndicators use quickbooks and run a portal through juniper square or appfolio or another 3rd party software companyOnce you outline your pain point happy to provide recommendations

He can try to work out a modification of the loan in some way, and there are literally dozens of different types of modification that may be appropriate for any given situation and may prove beneficial for both parties.  

In my case, I have residential rentals in one LLC, commercial properties in another, self storage in a third, and my real estate company operates in a fourth.

This part, I don't know so much about.if you need more info, feel free to reach out.

I'm looking at the bottom third of the market to focus (in Boise that is under $450k).