I have two suggestions to make navigating a bit easier.
Zoom - target box:
this would be my first choice. Maybe hit a hotkey to activate it. Click once to pick the camera target (like we already have) but before anything moves, out from that point comes a window box (the point would be it's center). Click again once you've got your box and we zoom to that box.
Rhino has that, but it takes a couple clicks or you have to customize a hotkey. Ctrl+W, then "T" if you want to try it out. That's pretty much exactly it.
Zoom Selected:
This is a good one too, but less useful for large parts. Although useful if you are zoomed in and want to quickly zoom out to that large part. I think it's self explanatory for the most part. Just zoom to the bounding box and make the camera target the center of said bounding box so you can easily rotate in space around the object.
I agree. These are definitely things we need. It's on the list.