The sit start is more of a hanging start if you're short, because you can't reach the hand holds with your butt on the ground. Traverse to the right and exit with a cool mantle.
For me the trick was to creep the hands along the ledge to make room for the left heel. Then the mantle goes with a high right heel, but the trick here was the placement of the left foot to initiate the rock over.
Rain sucks, but broken holds suck even more. Remember, never climb on wet rock in Fontainebleau.
The sandstone becomes brittle, and pulling on it will ruin classic problems. Drying it doesn't help, because it's still wet and weak inside.
All you can do is wait for better conditions.