The issue with your programs not working in 17.1 might be due to the fact that the default DE uses Wayland. Zorin 16.x used xorg/X11. In 17.1 you have to change to Zorin Desktop on xorg by selecting your username, go to the cog and change from Zorin on Wayland to Zorin Desktop on xorg. Once you have made this change you don't need to keep doing it every time. I suspect that Gnome is also getting more hungry for resources with the latest versions deployed. It is interesting that it is causing havoc with your battery compared to 16. My advice would be that if it ain't broke don't fix it. I think you are still good for another 12 months or so on Zorin 16. Perhaps problems like yours might be fixed by then. It might also be better if Zorin 17.x defaults to xorg and not Wayland for upgraders!