This is just the normal operating costs, never mind the big things that come up occasionally with capex like when you have to replace a major component (furnace, water heater, sewer line, driveway, steps, deck, windows, roof, doors, siding, landscaping, etc,) and it costs $10-20k.

If they put up any sort of resistance, that could be a cue to start digging a little deeper and documenting a bit more thoroughly (hence the doorbell camera coverage tip I put first - installing the cameras right away and then having the new lease conversation with the tenants afterward is very easy to frame as "I'm just a new owner putting some TLC into the property and doing my due diligence on the leases/tenants"; talking to your residents first, finding out they have extra people living there who aren't on the lease, and then installing cameras around the property could set you up for a very adversarial relationship with your inherited tenants). 

If there is mold, it will usually be A) on the subfloor exterior, joists, and insulation in the crawlspace, or B) in any areas of water damage/water leaks inside the walls, behind tile in bathrooms, etc.

Anyone have a recommendation on a company for a hot water heat boiler system replacement? 

We did notice some water damage in the front of the house but was told the roof is in good condition.

Of course, if it concerns water, that is an emergency.

Two rentals I have, the water has to be in the owner's name.

If one system malfunctions, you'll be out of the water.

Also utilities and sitework should be less as you do not need to bring in two electrical services, water services and run two sewer services and connection fees.

Is it not problem that they do not have enough water.