I would say, regarding the footwear, that the cats are just trying to understand our strange human customs. Obviously, we humans put great stock and care into our shoes (compared to kitties that wear none) and since the shoes tend to be on kitty face level, it is the human craft that they encounter most often and they are trying to relate to us.
You know, strike up a conversation, like the weather.
As for cats in mini-skirts, weeellllll... this is SL. Lots o' mini-skirt wearing going on here.
