I noticed these shortcuts pretty quickly when trying to edit text in geany and other apps. All the ctrl-shift-arrow key combos have been text editing shortcuts for most of my *nix computing life, so if anyone is counting, here is one more vote to change the defaults.
Seeing this post finally motivated me to open rc.xml and just take the shift key out, so that ctrl-arrow switches windows now. Off the top of my head, I can’t think of conflicts that are showstoppers for me. But I usually cycle through windows using alt-tab, so the most important thing to me is that these shortcuts are anything other than their current defaults.