Gay,
I do not mean to instill uncertainty into this discussion. We can find the answers to waterproofing and glassed forward bulkheads. It'll just take a little research.
I will say that Lorelei's forward bulkhead was glassed in all around its perimeter, and when I rebuilt the interior (see the article in the Library. Maintenance and Repairs), I glassed the new bulkhead in. Indeed, my effort was to make the forward compartment air and watertight, and so far, it appears that has been accomplished.
There are two inspection ports in the rebuild. One on the forward bulkhead and another on centerline of the settee's horizontal surface in front of the mast, just forward of the intermediate bulkhead. This port is positioned directly over the place where any water would collect should it get into the forward compartment. I take one of the bulkhead covers off when moored, or during the winter to allow for pressure changes and potential evaporation.
Not that it will do you any good, because there is no way to know the volume of flotation in your boat, but it is generally thought that Ensigns need to have a minimum of 40 cubic feet of flotation to keep them afloat. More than that is obviously beneficial, and the lower it is positioned in the boat, the better.
I think inflatable airbags under the bench seats is a great idea. Airbags would increase the freeboard of a swamped Ensign and would almost certainly assure the possibility of self-rescue.
Swamping is such a rare occurrence, but I've seen it happen in two situations:
1) Mainsheet did not get uncleated in a really big gust.
2) Sailing too deep with a spinnaker in big breeze (22+ knots).
#1) is why I really do not like the Oxen block. It just becomes too hard to uncleat when it is really loaded up. It is much easier to pop the main sheet out of a cam cleat.
#2) hopefully has been resolved with the advent of the 12 foot whisker pole. Wing on wing in big breeze should enhance really deep and stable downwind sailing.