I totally agree with you on mouse input. I was only using it because the keys weren’t doing what I wanted.
As for key commands, changing the up/down to chromatic pitch changes is one of very few changes I’ve made (although I recognize it may have far reaching consequences), and I know I’m not alone for that one from being on the forum (Jump bar: unable to use arrows because they are set as key commands - #3 by CMS_LU).
I’ll try resetting the key commands and see what happens. Having said that, the mouse input also doesn’t do what it should (ie. text hover preview in the tutorial), so I suspect it’s not just that.