By all means, you are not nuts, MP. I totally agree with you. I really don't know why Mark Wilson felt the need to create a new "trapeziod" nav deflector, but he says it's something to do with projecting or extending the deflector beam along the flightpath of the auxiliary craft., and the curve at the top is necessary and that's why the torp launcher had to be shifted to under the secondary hull.
I'll type in what the schematics actually say when I get home, just for completeness' sake. But I do think that a standard nav deflector, or even better, the one from the Belknap class, should have been used. Go figure.
That said, he obviously put in a lot of work to these schematics and I feel bound to honour that effort by matching it up. I'll be keeping my own Belknap deflector, but I think his plans do make more sense with no forward shuttlebay.
Look at it this way: If the entire length of the secondary hull is a hanger, where does the linear intermix shafts/warp core go? It couldbe done, like the turbolift shafts we see in the TMP Enterprise's hanger bay, but it would obstruct the flight deck.