oh yeah, event on event problem, XD didn't think of that.
derp moment. i was actually thinking as I was typing, so, XD.
yeah you can't remove replaced walls from the editor, but if you made it as an event item, you could remove it just like it was a table. But you still can't place anything on to the wall, so yeah...
SO! If you could get it where you could place event on event, THAN you could add and remove walls! hmmm this needs to be looked at more, XD.