Wow, I only meant to get some thinking going on not to throw a major wrench into the machinery.

But seriously, there are differences in house sitting situations. There is the house sitter who perhaps feeds animals and waters plants for a weekend to a couple weeks. Then there are house sitters that stay for several months or more. I have known a person who actually had a full year house sitting lease in which she paid a very reduced rate knowing that the family was planning to come back in a year and could come back with only a short notice.
In my neighborhood there is no need to consider the issue. But we only have clues as to who rents and who is living there. The association exists to ensure people keep their houses up and mow the front entrance.
If it was an issue, then I would personally be inclined to allow a longer term house sitter to access amenities
if said person signed a copy regarding the rules of use. (No I wouldn't give them a full copy of the documents as that would just be overkill.) I might include such things as that the grass must be kept up and such though.