All I can say on this SS6 besides "hell no" is:
Don't make the torpedoes any stronger, they are already stong enough.
Increasing the reload, air, and displacement is acceptable. But not too high on the
displacement... A full level 120 crew without decreasing any rookies on an SS would
be bull crap.
As for a PSS.... Idk... I guess they could make one. But it would have to be equal to
less powerful than an SS4. Because if you think of it... the PBBs are just better than
a BB2, but not as good as a BB3.
So the PSS would have to have the same.... (lack of a better word) limitations as the
PBBs. Maybe have them equal to an SS4 in speed, air, displacement, and dive ratio...
but have the damage for the torpedoes be less of the SS4. Maybe equal to the
SS3's torpedo damage. Also maybe lower the Torpedo Splash damage, as the PSS
would be boughten, and that would mean you have skill in a sub, So less torpedo
splash damage would be a challange.