Bulkhead/genoa screws/chainplate fixes
Iagree with rebedding --- use silica gel in all deck fittings.
On your bulkhead ... indeed what caused it? ... (likely leaking gaskets in your heads pump?). But for the repair using a two part epoxy glue will simply allow you to insert a new piece to fill your cut out area and will add not subtract strength. Just enjoy the versatility of epoxy!