So...after posting my initial question and correcting my previous errors by making sure all options are off before the end of each turn, I still find Shogun 2 crashing after 2 turns, every time, even if I close the trainer (after turning all options off), still crashes. I checked out the message board on the subject and someone recommended rolling Microsoft Visual C++ back to the 2005 version. Did it. Nothing new happened, game still crashes. I double-checked the readme file to make sure I didn't miss something before making this post. If anyone has suggestions, I would be very grateful.
Running Windows 7 Home Premium for OS
Fixed it! Sorry for the trouble, but after hours of troubleshooting, I found that downgrading my Microsoft Visual C++ back to 2005 AND running Shogun 2 in compatibility mode for Windows XP service pack 2 did the trick. Hope future people find that helpful.