A lot of water damage to the entire subfloor, the bathtub was tiled, but not sealed properly and black mold was around almost all of the grout.

Landlord paid hot water will require you to install individual hot water heaters and run lines.

Other coverage to discuss would be Water backup and equipment breakdown.

Location is prime and has lots of water, wild life, fish, birds.

Your capex budget for a condo will include appliances, hot water heater , floors, maybe hvac, bath and kitchen remodel.

I would also add in some number for "reserves" on a monthly basis for each unit, perhaps $100-$150 per unit per month to start; you want to make sure you have some funds available in case you need to replace a roof, hot water heater, etc...

So, our regular plumber mentioned that the price of water heaters looks like it's going up significantly. 

Unless the property is under water, that seems expensive.

From my research the fees go towards hot air heat (from what I read about the property is the association pays for oil), water, snow, trash and grounds maintenance. 

@Mike Gonzalez keep it simple, its gross rent less taxes , Ins, PM ( property management, 8% of gross rent ) 5% for misl, and any other expenses, snow, lawn , water etc, divided buy your PP.