They in fact have broken the lease. 

Replaced broken appliances.

.- Strip blinds, lights (leave naked bulbs to have light to work with), electrical faceplates, door knobs, baseboards, any screws on the walls, wire shelving, toilets (leave one for use), broken mirror, cabinets in bad shape, storm windows, shower heads, faucets, damaged tubs (and surrounds) and shower stalls.7.- Repair subflooring, ceiling, walls holes, replace wall panels, door jambs, window sills, battens and trims, subflooring, electrical switches and outlet receptacles, etc.

Investment Info:

Single-family residence fix & flip investment.

Purchase price: $70,000

Cash invested: $91,000

Sale price: $204,500

Foreclosure property, needed foundation work in addition to...

I don't want something to get broken, theft accusation, a door left unlocked, pet got out, pet isn't secured, etc. have a he said/she said argument on who is responsible.  

When a tenant moves the average cost to paint, install carpets, repair or replace a faucet, toilet, broken kitchen or bathroom sink, etc. is never less than $2500.

With a multifamily property there’s almost always someone in one of the units operating like a built in safety net minimizing your losses from non-payment or times of vacancies (remodels/repairs, broken leases, etc..) in one of the units.One more reason to invest over buying is as the equity grows. 

Either way, I personally think its foolish to replace such expensive systems that is not broken.

I'm ideally looking for companies that have experience with larger homes and who also have basic maintenance capabilities to address issues like broken toilets, replacing HVAC air filters, etc.Any response here or via DM is appreciated, thanks!

The broken vent pipe and disconnected shut-off valve should both be pretty simple fixes, maybe $200 - $300.The gas fireplace would probably have to be replaced and could cost $3,000 or more depending on what you get.