So... I know you sound like you've pretty much settled on this turret-ish torpedo launcher design... but I just wanted to throw this out there.
You know how your and most trek torpedo bays are oriented horizontally? That is, if there are two launchers, they're usually side by side. What if you stacked them vertically and gave them more of a vertical alignment? I think especailly in the neck it might not make them look quite so bulky or stick out quite so much.
One of the main problems with the upper photorp launchers is that their line of fire is already dangerously close the lower sensor dome on the saucer section. Stacking them vertically would only crowd the dome even further. Chances are that I'm going to make some further changes to all of the torp launchers but a vertical arrangement is probably not in the cards.