Some of that doesn't look like kid mess to me. Is that a vaccum cleaner and boxes of unopened tinsel in the room? (or is that a stack of computer paper?) Those stacked plastic bins with stuff on top of them? The stroller? (or is that a car seat? Can you put the stroller in the hallway or in the car trunk if you have one? In the bedroom? Hall closet?
I find my kids are better at not doing crazy things if there is some ryhme and reason to begin with. Some of it can't be helped when you live in a small home, but purging frequently helps me.
I was thinking the same thing. We did a massive de-cluttering project this summer and it really helped to cut down on the big messes in our house. I get reallllly overwhelmed when the house gets in a major state of disaster and DH hates clutter. We purged a BUNCH of stuff--sold it or donated it and it was a great thing for our whole family!
About the laundry--my son is 3 and he really likes to unfold and throw our freshly washed and folded laundry too. : I make sure it is out of his reach or just put it away right away so he can't get to it.