However, what extra steps do i need to take to make sure she will do as she says?  

I just wanted to get some extra details to make sure I'm relaying the information correctly.

I personally never hear stories of the turn key provider spending extra sound proofing between units or investing in better quality fixtures or other high touch building materials so that the end buyer can enjoy reduced maintenance costs and better tenant engagement.

You'd just need to be extra diligent about your research and have a solid team on the ground there.

Once you have the difference, assuming that both options fully pay the mortgage, consider wether or not all the little tasks you do daily while self managing are worth the extra income.

The reality is the opposite - if it's not in writing then the PMC doesn't have to provide the service or can charge extra for it!

I know that what I'm asking is high for a 1 bedroom, but it's really large (1,200 SF), and has 2 extra rooms (altho they shouldn't be bedrooms because no windows). 

All the county told me is that I'll have to do some landscaping work, add extra parking spaces, but I don't know anything about the stormwater plan. 

A contingency in this case means setting aside extra funds to cover any unexpected cost increases during construction.

Lining up back ups (back up contractor, PM, extra reserves) won't hurt as well.