When would I need to secure items for installation like the kitchen cabinets and toilets, etc.   

In Florida where I live, those two items cost me about 25-33% of my monthly income on a LTR.  

You'll want to ask for an itemized invoice if they do not adjust downward significantly and plan on spending some money on an attorney to come up with a strategy. 

I am 29, single, employed, have ample savings, a full VA loan, and am pre approved for 550k, and looking within an hour of the dc metro area, ideally Harford county MD due to the good schools and military bases near by. 

Sometimes the 20 or 30 year of 'relationships' they reference as an item of value can in time evolve into a relationship of contractors, subs and suppliers, looking out for each other, not necessarily the builder or project owner interest.

I have 2 rental properties.The First is in Crestview FL with a long-term military tenant.Cashflows ~ $800 monthly.Mortgage is $180k.

Fort Walton Beach is very consistent due to its military bases and constant rental demand. 

For a $20K home, what happens to returns if major capital items are needed after year 2?

Strong job and population growth, plus VSU and the military base are steady growing.

And are there any expenses that go on my itemized deductions?