My goodness, what a lot of odd people there are! I know everyone has their own little peculiarities, but to impose them so strictly on guests is baffling. I suppose some of these rules makes sense - no shoes in the house, wipe down the shower, etc, but the ones about water usage baffle me - what the heck? Surely water, even if metered, is affordable? Agree that some of the thing mentioned would seem to hint at mental health problems such as OCD?
Re the Greek no-paper-down-the-loo, I used to live in Turkey and it was the same. I thought it was vile, but actually the loos all had a copper water pipe sticking out from the back of the bowl, and you were supposed to wash your bum, so the paper going in the bin would only, in theory, have water on it .... same in Greece etc I expect. I remember a friend visiting me who asked if the pipe was supposed to go up your bum ...
Also, as a northerner, remember my grandma's house with its 'front place', where no-one was allowed to go. I don't know if even the Queen would have been let in there.
Mine is very tame - when we go to visit the PILs, about 2 hours drive, we do not get offered a drink unless we arrive at one of the designated times, such as 11am for morning coffee or afternoon tea at 3.40pm. I now insist that DH asks them as soon as we arrive - took him a while to work up the courage.