Yes the plugin works in both versions of FCP

Yes, due to utilizing shortcuts, US English Keyboard layout is required for this plugin for now. You can change keyboard layouts in the System Settings. You can also allocate a button such as the FN key to quickly switch between layouts.

If you have actions that do not work make sure that the US Keyboard layout is selected and that the Logi Plugin command set is set as the default command set in Final Cut Pro -> Command Sets

This plugin is optimized for systems that use the M-chipset processors. It can still be used with the older Intel processors, however some latency can occur depending on your system specifications.