When I owned hull #2 I lengthened this post up to the cockpit floor.
It is something that was added in around hull #40 so none of the
older boats had the post that went up to the cockpit floor. It merely
stuck up about 6-8 inches so you could attach the outboard to it. The
problem I was having was the weight and flex of the cockpit was
causing seperation at the forward cockpit bulkhead from the cabin at
the outboard end next to the hull. I believe this is why the support
was added later on the newer boats to prevent the flexing of the
cockpit and prevent seperating of the bulkhead.
I have never heard of the post causing the bottom of the boat to
become deformed. I would be inclined to remove the post completely
and cut through the inner layer of fiberglass. It soulds as though
there may be some core damage underneath the post.
When I replaced the thru-hull fittings for my instruments on hull #2
I found a LOT of water between the two layers (i.e. - in the core). I
had a small steady stream of water for a day or two draining out of
the boat when I drilled out the old thru hull pieces. I ended up
leaving a heat lamp on it for a couple of weeks before I was
confident it was dry. Sounds like you may have a similar issue in the
back of the boat. Maybe not but probably worth looking into without
too much pain.
I think moving the cockpit support forward would be a good thing
overall.
Keep us posted as to how it turns out and what you decide to do.
Jason