Hey JacketyJack, thanks for the additional info!
Some Win10 machines definitely seem to have an issue with the win64 and win32 versions of the game (where the game doesn't even launch) - but if Java has been installed, the .jar files will at least run. There's probably a problem/conflict with the bundled version of Java I'm using with those versions.
As for the mouse issues, I'll post a sticky thread to mention that Gigabyte machines might be problematic, so that maybe some other people could add their 2cents in case that's the source of the issue. Still going to keep trying to figure this out.