New appliances, outlets, switches, and mitigated for lots of smoker damage What was the outcome?

Rehabbed house, repaired termite damage, new hvac, and ducts, toilet and shower, and appliances, granite, new windows, new flooring, wall replacements, all new switches and outlets, new screened florida room, and tiling on front and back porches.

Seller left TV's in the home, when they were removed we found the TV's were improperly wired directly into the outlets and painted around.

Those who have experience in this area, what would be any unexpected downfalls of this method that a new investor would not typically be prepared to confront?

You'll find unexpected replies, all from investor perspectives. 

It could have been a bad breaker, overload, faulty outlet, faulty appliance, etc... 

HUD's Housing Quality Standards guidance on ungrounded 3-prong electrical outlets states that they're acceptable if protected by a GFCI outlet.

Replaced ungrounded two prong outlets with 3-prong grounded outlets, added GFCIs, new light switches.

One inside they are generally qualified to check the mechanicals including electrical systems, breaker panels, junction boxes or lack thereof, knob and tube, outlets (condition and grounding) GFIs, etc; Plumbing systems check include hot water tank, faucets and drains; HVAC check; etc.

Long story short, a sewer scope is always worth it to avoid unexpected surprises.