You should NOT "help" the seller in certain circumstances, no matter how pure, sincere and full of Godly intentions you are, if they are in foreclosure or pre-foreclosure and live in the state of MD.

Couldn't get the water turned back on without an inspection.

In my experience, many insurers will cover the house but not the roof, ensuring you have protection against fires, broken water pipes, falling down the stairs, etc.

Also, if the tenets already pay for their own electric and gas can you use RUBS (if leagal) for water and sewer?

The more you can put down typically the better. you also though want to make sure you have enough money in reserves for rainy day - such as a hot water heater breaks or something.

The cabinet under the sink had water damage to the base, and I have the option of just repairing that and painting the inside of it.

Quote from @Bryan Waters: I love the ADU play. 

As someone who lived in Satellite (behind the CVS beachside), I will say the upkeep with the salt water was tough, but the area was phenomenal. 

You are not required to pay upfront costs (and shouldn't, in my opinion.)I require written verification from utility companies (water, gas, electric) that utilities have been assigned to Tenant effective the first day of occupancy; no confirmation = no keys and lease approval withdrawn).

We made several improvements to the property when we got it - a totally new gas line, a totally new water line including all the lines from the street and pex plumbing installed.