On the other hand, hiring a GC provides a one-stop shop with streamlined communication, experience, and expertise.

There's a lot to be gained by selecting your items and putting them in your shopping cart (online) but not yet checking out so that you're ready to pull the trigger once you've closed, especially if you're doing MTR or LTR.

Small shops just wont have the resources to train a new agent properlly.

If after that deduction, and all other deductions you still have cash flow, which is unlikely, it is a candidate for hold however based on your description of the handy work I would guess it to be a maintenance pig that you would be safer to unload now and move on to other endeavors that will have a better chance of being positive cash flow. 

The only thing I can think of is shop around for different insurance, and make sure your property tax assessment is at or below the appraised value of your refinance.  

With all due respect to the development big firms out there, my project is very small and I believe I'd be best served by a small firm or even one-man shop, and frankly a bigger firm will likely not have time for a small deal.I simply need a low-cost conceptual plan that I can use for marketing to builders.

Got to shop around and see what is offered.

I'm not sure if the owners have shopped this around to the Apartment brokers already and they've all passed on the deal, or the owners don't know what's going on.

Or is it safer to stay away from a potential good deal because of the inherited tenants?

I was going to pay the full asking price because 1) the numbers still worked and 2) like you mentioned, very little inventory to shop around