Things you might want to try:

Run ShogunM.exe/ShogunW.exe with the D command line switch to force native desktop resolution and colour depth settings.

To test this out from the run command dialogue box or from cmd:

Code:
ShogunM.exe D
Caveats: You'll need to set your desktop colour depth to 16 bit colour. STW (and MTW) use 16 bit colour depth and most modern windows desktops are set to "32 bit colour").

This will run the game in an "overlay" on top of the desktop.

Pros: It avoids the problematic mode switching which can crash the game.

Cons: The game runs in a smaller overlay "window" (not a window) overlaying your desktop. Edge bump rotating the battle map camera doesn't work and edge bump scrolling of the campaign map doesn't work (doesn't bother me as I've always used cursor keys anyway).

You can also try out the Windows 7/8.1/10 compatibility settings.

Since Windows 8, I believe 16 bit colour depth support for the desktop was dropped. You can run the programme in "reduced colour mode" compatibility mode. You should also run "legacy" 32 bit programmes from the Windows 98 (Win9x) era in "run as administrator" pretty much as standard on any Windows Vista/7/8/8.1/10 installations.

There is also a "run this program in compatibility mode for" option. Just select the earliest Windows version it offers or XP/2k.

Also remove/rename the intro videos.