So, I told the tenants that I would cover water up to $x then I will send them an invoice each for 50% of the rest. i.e.

Surrounding homes are around $200k + with similar plot size and sq. footage.I put in 40k desired profit to cover $15,000 paid to lender plus in the closing costs a point fee of 3% (Agent fees portion)These numbers look average correct?

I have a large pool of handymen that cover every aspect.

I want to find deals in December, but I'm worried about covering payments with vacancies. 

@Eder Aldana, @John Jacobus covered all resources that I am aware of.

Is your new investment making enough to cover these loses and still be making you a good ammount of return?

Covers all expensesHere is a iink that may interest you, one of my recent cash cows. https://www.biggerpockets.com/forums/311/topics/624369-my-little-cash-cow-in-detroit

I would suggest screening all the existing tenants before you commit, if you can, if not get the PM to do that.

Proper screening, at a minimum, reduces the chance of dealing with violent criminals. 

I am currently renting out three of the rooms which covers the full mortgage and I live in the 4th room (So house hacking).