The key to any of this are the partnerships...with your other GPs, brokers, property management, CPAs, and attorneys...this is very much a team sport, and the best way to play is for all sides to win.

Do you charge for monitoring and maintaining vacant units?

Not sure if you can answer this, which it's fine if you can't, but I am curious about legal documentation when structuring the deal with GPs and LPs.

If you do this right the rest will be pretty simple (although you should continue to monitor payments and expenses and ask questions on occasion)B)  Medium effort - Use @Hemlane. 

Bigger Pockets has some great state forums and usually there are good locals that monitor those.

Work done as an investor includes (1) studying and reviewing financial statements or reports on operations of the activity, (2) preparing or compiling summaries or analyses of the activity's finances or operations for the individual's own use, and (3) monitoring the finances or operations of the activity [Temp.

The plan though is to sell the house in two years and I wouldn't want to sell anyone something that wasn't built right,You would want to lay the concrete / cement below the leveler in all of the cracks (don't count on the leveler to fill them), then use schluter ditra below the flooring if you're going to use tile.Ditra is expensive but worth it - https://www.homedepot.com/p/Schluter-Ditra-54-sq-ft-3-ft-3-in-x-16-ft-5-in-x-1-8-in-Thick-Uncoupling-Membrane-DITRA5M/100143471Otherwise, based on the info given, I would focus on drainage and monitor the situation.  

Mine can set door codes, message (or call) guests, schedule cleaners, adjust the thermostat, monitor my cameras, & call a plumber just as easily as a local PM can, for 1% of the costI wrote much more about leveraging offshore assistants in this post here.

May have to get cameras and/or security monitoring to prevent it from happening again. 

I would also recommend you have a good network of people wherever you are looking to invest to monitor your property for you and keep you updated on the progress - best of luck!