Currently working on my network, planning systems, and reading all the books that I can get my hands on!

I'm local in the Dayton market and designed a system to combat this very thing.

My own basement was dry for a decade . . . until we did some renovations/additions that accidentally messed up an exterior drain system . . .

If they are good tenants, stop treating them as if you are a slumlord.Or, you take money off the rent and have them fix or supply a washer system they can take with them when they leave.Need to state so much in a lease addendum.

I have a friend who’s landlord keeps neglecting to replace their broken HVAC system.

Trying to tackle collections can be tricky like looking at the date of last activity and managing the negotiated payoffs correctly.Banks have a system where we can run "what if simulators" and rapid rescores. 

What about heat and AC, are they all separate units or a central system?

There could also be an issue with the auto defrost system and the water dispenser may be the first symptom.

Also invest in the best security systems you can get and do everything else you need to be safe.

I assume you got an inspection and that's where this is coming from, and I would suggest it would probably be better to become more learned on systems before making offers than just waiting for inspectors to tell you the obvious and hope to beat down the seller on price.