However, you're missing closing costs and down payment estimates, which could impact the analysis.

Insurance estimates?

Given that the property is in "a rough area", I'd estimate 10% vacancy.

Having 5 units also does give you some protection if 1-2 units have tenant issues, which is good.The estimated closing costs of $3,000 seems a bit low to me, but that certainly varies widely from lender to lender and from area to area.

Once you know what kind of tenants you have and their living habits and periodic inspections of their unit, you get a good feel for things and a good estimate of what you will be doing in repairs and improvements over the years.

Competition across the street does have rents at our potential estimated rents but a few more amenities are offered such as pool, pets, vending machines, etc. 

I've been starting to look into the Tampa Bay area but was wondering if anyone could give me some advice on how to accurately estimate construction costs and ARV in a new market, as well as on how to make sure you get a fair price on labor.

In this case you will be accumulating more cash while owning an asset.

I just think that’s more than counting up how many vacation hours we accumulate each pay period..

What would be the estimated cost to fix the issue if it isn't extensive and can be accessed (I am assuming dry rot in garage the way it is described).