They paint a glamorous picture to get you to sign with them.

But I had to go behind and redo some of the grout, retouch some painting, tighten some plumbing.

I have had some painting work done for my rental which I want to claim as a maintenance expense.

You can not like the color of the paint and back out on that clause.

You hire a work crew to clean, paint and repair the 4 units. 

This is essentially just paint at 1k per unit. i would want more than that but your inspection would tell you all you needed to know-in a 16 unit, they would be (should be) on separate electric meters, which would be billed to the tenants, not you.

Everything mentioned plus lead paint and asbestos.  

Roof is original (Shingle) $4k is as I expect to have to put in about $1k each unit in some shape as carpet, paint etc? 

If this is your first build, you need to think about level of finish on the Sheetrock, paint, lights, floors, underlayment, etc.

Then insulation, then drywall, then paint primer, then flooring, then cabinetry and interior doors, then base and case, then the balance of the finish work.