I hear you on how they get into everything! I have the same situation with older cats and now four youngsters. They are so much fun but some of the ways they entertain themselves isn't.
Mine like to knock things off to watch them fall and a new one this week is to pull on a towel to watch it fall to the floor. I can't wait for warmer weather and I can start walking them outside - blow a little stink off of them!! The play-time in the house is just making them fitter, I'm afraid.
Thanks for the pics. Someday I hope to learn to post some...