Challenges?

So I get your hesitation to be too demanding and your desire for the problems to go away as fast as they can, however since you have NO property manager ( I don't use one either), it is incumbent that you take a more ACTIVE approach with management of your property.Let's review your situation.  1st time leak occurred, you sent a plumber over to find the problem.  

If this is your approach, you will end up eventually get a bad taste of the lending industry as a whole.

Challenges?

Most traditional property managers don’t handle this setup due to challenges like managing tenant disputes, coordinating overlapping move-ins/outs, and the risk of Fair Housing violations when selecting tenants.

If the house is under water with the OCWEN mortgage, then approach the mortgage holder about a short sale. 

It sounds like you navigated the challenges well and gained valuable lessons for your next venture.

I applaud you for putting it out there but 1) maintenance/cap ex is far too low for a duplex 2) no PM. 3) vacancy at 1% will be challenging if achieving near market rent.

Add the financing challenges and that you existing structure likely will become rent controlled.  

Challenges?