Cary, that post should be a sticky in the starship design and construction thread ... if there was one. As you explained the forces, I immediately saw the warp nacelles as wrenches and understood much better than before the difficulties involved. Suddenly, the 1701-D looks like a much smarter starship!
It is. I've never really been fond of the "style" of the 1701-D, and I don't care that much for the eggshell-thin nacelle pylons (which should be straighter and thicker) but otherwise, yeah... it's a better design overall. This is, in large part, due to the fact that Andrew Probert "gets it" regarding practical design. He may not be a PhD science guy, but he brings to the table the same things that Matt Jefferies did... practical understanding of "why things work."
That's been my biggest issue with everything I've seen in Trek since the beginning of TNG, really... technical matters being addressed by people who clearly have little or no real grasp of the real-world considerations, or in some cases being addressed by people who do "get it" but who are being directed by people who don't know and don't care about real-world concerns.
Where things are made to "look like they do something cool" instead thinking through WHAT they do, and WHY they're the way that they are. That approach leads to bad decisions and bad results... even if they spend more than any other production has ever spent to get to those results.