I'm not observing the same profile in terms of memory usage you are via task manager, but the other details seem consistent. Cargo designs from my faction will crash the game to desktop whether I wish to add/subtract engines, etc, or draw from the template and add things from scratch.
It's inconsistent with medium designs. I can draw from the template and create a new design from scratch, but modifying the premade designs will crash to desktop.
I don't think it is my custom faction ship set. Why hasn't it been an issue until the other day? I can only guess that something went wrong with the patch, or the steam client update the other day may have broken something. It may be windows 10. Either way, it's really freakin' aggravating.
Getting the E drive error is my only current lead. In device manager, a usb hub had taken up that directory letter. I uninstalled it because there is absolutely no reason I can fathom that a usb hub would need it's own directory, and there are known 'ghost drive' bugs which people encounter. This leads me to the question -- what could galciv 3 need from a non-existent E drive? The hub connects to a G path, for an external backup hard drive... Hmmm.