Just checked the thru hull location and there is no backer in that location. The y-valve has a backer but it's up higher on the hull. And 2 inches on the bottom would not be out of line as this is where the keel
is bolted on and the extra stiffness would be needed.
As far as the ballast ratio is concerned the STIX value is more pertinent to newer designs. The Jeanneau 43 is rated 44 STIX value. “A” (Unlimited Ocean) STIX Value
>32 - adequate to withstand up to a force 10 gale, with average waves of 7 m height and eventual wave heights of 14 m.
And yes I would prefer a proper seacock over the ball valve. But I will change them out over time. That said none are in locations where the could be damaged easily by stowed gear
moving around. Just another maintenance
issue to keep tabs on.
And before anyone brings up the iron keel
, yes it needs more maintenance
but properly cared for it will last a lifetime.
I'm not saying this is the best boat out there but you get a lot bang for your buck.
Sorry for the delayed response but we have been out sailing and not varnishing teak