I offered to pay the difference of what it actually cost him and 3months rent (so if billed labor was $3k, I’d just pay the GC $150).Reasons why I like this:-Building rapport with this GC and his businesses-I get my reno done professionally at a heavily discounted price or potentially free-unit was going to sit empty anyways during my deployment, but now has a handy guy living in it-short term deal with the GC, at most I would sign a 6 months contract and charge the actual amount beyond the cost of renoThings I am getting done:-Laminate floors install and base boards-Cosmetic touch ups in bathroom (to include dry wall)-new front door/frame install-putting up ceiling fans -replacing cast iron pipes for sewer linesWould it be a good deal, all things considered?

Replacement Property Must be Same as What Was Identified.

Is there any capital expenditure items (HVAC, Roof) that will need repair / replacement in the next 3-5 years?

I would ask for a $25k roof allowance or ask them to replace the roof now. 

We had a new water service line run 1.5 years ago and replaced the curb trap at that time when everything was exposed.

I can repaint or replace dog damage in a day, next tenants would never know. 

Examples: I take a refundable pet deposit instead of a non-refundable one or a monthly fee, I currently pay the whole water bill without taking money from tenants because the duplex is watered together (I will eventually get a separate meter but the outlay is more than I want to pay right now) assuming it doesn't get out of control, paid for the new doorknobs on the bedrooms because the tenants requested locks despite the lead tenant saying they would pay for it, planning to replace the microwave hood simply because it's louder than it should be though it still works, etc.I'm probably losing out on a minimum of $100 monthly.

Do they all need to be replaced to.

@Jacob PhillipsAt a minimum (beside from your security deposit), you should have cash on hand to replace one of the major mechanical equipment (often the AC/Heater units).   

According to my research the work I am looking to do (replace the tub and surround with a one piece caulk free tile free tub-surround product and replace the vanity) should not take more than a week.