All major moving parts and appliances in the home seem to be in working order water runs toilets flush theirs heat but no central A/C, fuse boxes with mostly 2 prong outlets.

Say I close today, I list today, oh, but wait...I decide that before I move someone in I'd like to put in a new vanity and toilet, and by the way, i don't like the floors so I'm upgrading them as well. 

If I cleaned the apts...I mean really cleaned them...got down on my hands and knees and scrubbed the toilet bases for example....I wouldn’t want 100 units.

If you flushed the toilet or ran the water in the bathroom you could watch water run down the plumbing stack in the basement! 

It is pretty simple.Clean everything.Professionally clean carpets if applicable and provide receipt (your lease or addendum) should say this)That include stove inside and out and new drip pans if applicablefridge - empty and cleanbathroomsceiling fansNo trash left behindBlinds if provided clean and in good shape.It is just common sense stuff.I so rarely have to give back a deposit due to people breaking the lease.If some one leaves at end of lease after giving proper notice (per lease) they try really hard to get their deposit back  and I usually don't beat them up or stupid stuff. 

You may have leaky toilets and faucets or someone water the lawn a lot.

There is alot of equity sitting out there and folks who bought recently with $10k PITI may do ok but will take years to pan out if things turn out bad, ie. lose their job, use their savings to save their house, cannot find a job, notice of default, short sale, foreclosure, etc.Also as someone else mentioned, when a market crash happens, you cannot just show up at the party and start buying properties. 

The "high end" is those walk-throughs that involve 3D systems, being able to drag your mouse to pan around the rooms, etc. 

Same with small leaks in the toilets and drips under the sinks.

If your opportunity pans out, let me know.