The pool noodle idea is awesome!! Right now I have 3 pillows along the wall, they are pretty flat and old so I have them folded in the crack along the wall.
And we converted the crib to a full but it is SO high off the ground, so we have the boxspring/mattress on the floor, but there is a wood slat along the side that hurts if you bump it. It is lined with a towel but a pool noodle with a slit in it would be perfect!
So glad I read your post.. now the question is if I can find a pool noodle this time of year