This worked well at first, but I started noticing "ghost" charges for random repairs and services: $45 for a door knob replacement, $85 for wall repairs, $65 for a toilet leak, etc.

If you must, get video because with video someone can slowly pan across and capture almost every surface.

Something like pink and green striped sheds, ugly art like gold painted toilets.

I'm not overly interested in purchasing properties and having to deal with tenants, broken toilets, etc. - my day job keeps me pretty busy.  

For example:General-Filters (furnace, air conditioning, oven exhaust, refrigerator, and water)-Stove burner when the “eye” needs simple replacement-Batteries and remotes that service the premises-Fan and light pull strings-Smoke and carbon alarms testing and batteries-Ensuring appliances are properly plugged in, hooked up, and used-Removing dirt, debris, and lint in and from connection pipes (e.g. clothes dryer)-Tighten loose screws on all home functions (e.g. doors, hinges, handles, socket -Balancing off-balance appliances-Cable, internet, and phone jacks-Fire extinguishers-Systems operation (e.g. security, irrigation, HVAC)HVAC-Monthly A/C filter and drain line maintenance Electrical-Reset “tripped” GFI breakers-Light bulbs (throughout and at the end of the tenancy)-Blown fuses-Reset breakers in the outside and inside breaker boxes-Socket and plug outlet coversPlumbing-Unclog drains or toilets-Caulking around tubs and showers as needed-Gas pilot lighting-Leaky faucets and shower heads-Toilet flappers, handles, seats and seat lids, tank lid, and flush kit-Sink and tub stoppers-If septic tank present, use RID-X as directed on consumer box-Proper cleaning of garbage disposal-Loose faucets and sprayer heads and hoses-Faucet filters (i.e. aerator)-Open exterior plumbing clean out when necessary (e.g. sewage backup)Exterior-Routine lawn (and pool) maintenance-Adjusting sprinkler heads as necessary-On the last month of tenancy, tenant must perform required lawn maintenance no sooner than 2 days prior to vacate dateThere’s a lot to consider as a landlord.

If you're open to connecting, I'd like to hear how your scenario panned out. 

With the SRT we restock basic supplies between guests - toilet paper, paper towels, shampoo/body wash, laundry detergent.

Typically the leaks have been toilets which will constantly run and use water slowly.

Check out NOWi Sensors They have building monitors, toilet monitors, flood monitors and they focus on multifamily.

There are many potential downsides – dealing with vacancies, problematic tenants, maintenance expenses, and the proverbial call in the middle of the night to fix an overflowing toilet.