But would I feel competent performing surgery on someone without an expert's guiding hand?

As for the construction of the park, the plans will be put out for bid as a negotiated job upon completion, and we will be using a third party, general contractor to perform the work.

We put them to the test with an office warehouse 3 building 40,000 sq ft syndication 2 years ago and they performed as they stated.When utilizing local lenders who keep the loan in their portfolio, you CAN negotiate on rate BUT I find it much better to pay 1/4 to 1/2 point above the absolute minimum and obtain these other advantages instead.  

Once you have a shortlist, sign up for an account with each one and test them extensively to see how they function.

If they demand better performance, let them hire an A/C technician on their own dime and get a professional opinion, or they can terminate their lease early and move somewhere else.

It depends on: (like you eluded to) whether you are buying 1sts or 2nds, whether you want NPLs or performing notes, whether you want the property, whether you buy CFDs, whether you can wait 18 months for a foreclosure, etc.

Repairs vs. capital expenditures.Find out how long the provider has been doing cost segregation studies and how many they have performed.

The only potential problem is a very old and changing interpretation of the validity of doing this when performing a 1031 exchange. 

did they have you fill out a notarized affidavit that said you were self performing the work?

If 3 months, you could look to have closing stretched out so the loan parameters would assume you would take over the occupied unit.