They charged because we "touched" (remove the toilet, installed flooring, replaced wax ring, re-mounted the toilet) the fixtures.

That means that overflow from the bowl is able to get through the floor above, the subfloor, drop down on the ceiling drywall, and damage the drywall enough for water to seep through to the visible side AND damage the paint from behind.It seems much more likely that in the course of previous repairs the toilet was removed and put back in place and the plumber thought he got away with not doing the messy work of getting rid of the old wax seal and putting in a fresh wax seal Minor seepage from the unsealed connection and a plumber covering his hind parts seems a far more likely explanation for what you're describing.Maybe you could take a picture of that ceiling?

I really dislike particle board especially the sink base cabinet.One leak and they swell up, crumble and it's irreversible.Tenants always put too much stuff into their sink cabinet.  200 bottles of hand detergent, DW detergent, cleaners, bleach, comet, rolls of kitchen napkins, candles, extra kettles, and 500 supermaket plastic bags filling every air void existing in there meaning any minor leak will not be noticed by them until it's pooling on the floor.

I mean, I'm about to rent my house out, and the brand new toilet should NEVER clog, so if it does, I want to know what the hell is going on - is there a real problem, are they flushing stuff that could do real damage, is the toilet broke, the wax seal a mess, etc - a lot of damage could happen! 

He has since burned several cheap devotional candles 24/7.

I don't even allow candles.

Candles in the restroom to guide way to potty spot!

Nothing is ever easy" "Stop worrying about the problem and find a solution" "People would rather follow a torch that leads the way in life, then to light a candle and find the path themselves" "Vengence is mine say's the Lord"

Drunk roommates, a roommate leaving a door unlocked and there's a break-in, theft among roommates, one person lets tub or sink overflow, someone causes a stove top fire, someone leaves a candle burning, someone smokes, roommates get in a fight, etc.Plus noise.

The stuff lasts forever and you can strip and wax it and make it look brand new.