That will more than likely wash out the issue.

Wash, rinse, and repeat so you can put the minimum down payment.

If you don't, you need to keep a lid on things i.e. water saving toilets, landlord thermostats, keeping a close eye if tenants are having several other people live there, car washing services on premises, etc.In the end, it all depends on how it cash flows and your tolerance.

I would ask what was he thinking of doing first and now what has he added to the Job.I would then, as other people have suggested call in other contractors.  

My main concern was he wasn't licensed for plumbing. 

Friends experienced a similar occurrence with their new build up here last year.The home was not heated during construction but the dishwasher & washing machine had been hooked up & tested during the warmer days.

Asking about the car they are washing, the mower they are using, just anything to start a conversation.

I have 6 years experience in managing a construction company and two car washes.

My first job was washing cars at a local car dealership.

But back to your goal to get a 2nd property: the bank underwriters might only see the mortgage/ insurance payments as a wash with your existing rent since it hasn't been rented for 2 years yet.