I would pay attention to the top of the windows.

Furthermore, these houses are all made out of ship lap, which means they have zero insulation and single pane windows and the ones I am seeing do not have any type of central air conditioning.

(New stove , small plumbing repair , replaced a window that was broken)What was the outcome?

Sometimes it is better to buy something, where someone else already apid for a new roof and new windows etc..

These lines of credit typically have a 12-18 month window of 0% interest, allowing you to get in to a deal and then transfer the debt to something long term (or just sell if it's a flip). 

I connected with a wholesaler on Friday who sent me some properties, but they're in pretty rough condition (boarded windows, full rehab, potential structural and roof issues, etc..).

If you want to file a Police report and turn it into insurance, you could do that.If it's a window unit, they are cheap (plug and play), if it's a whole house unit, it's only part of the system, and you can re-buy just that part.You can get a Cage for window units and for whole house units.

Have done an extremely extensive full gut remodel (practically brand new home, literally everything updated/repaired from foundation, roof, windows, all exterior work, LVL beams to demo load bearing walls and create open layout, med to high end bathroom/kitchen renovations (master shower is floor to ceiling tiled in w/ double rain shower and ADA compliant, granite countertops, 6-8 person island, all new stainless appliances), all new electrical wiring, plumbing, etc., solid core doors, widened old 22' door openings to 24', new laminate wood flooring throughout, 5/8' baseboards/trim throughout, tankless water heater, tape/bed/texture/new paint on all new drywall), etc.I'd love to hold onto the property as I have no compelling event forcing a sale. 

Most of the windows are bad and something is wrong with the HVAC because there using window AC units..??

Not to be pedantic but.... aren’t delivery windows large & sometimes missed?