I *think* that there are two issues you are facing:
1. The nouveau kernel driver doesn't support your Nvidia GPU properly, which is why "I have to boot with `nouveau.modeset=0`, otherwise boot hangs at Plymouth after entering my disk encryption password.". But that doesn't matter too much here since the desktop will be rendered using the Intel GPU instead.
2. i3wm doesn't seem to be using compositing, so tearing and flickering is expected. Maybe you can configure i3wm to enable compositing, or maybe it doesn't support it at all. Either way that is a problem with i3wm only.
Only #2 is the real problem here. If you would like to avoid tearing then I suggest you will need to use a different window manager or desktop environment. Not i3wm.
Thanks Josh.
I *think* that there are two issues you are facing:
1. The nouveau kernel driver doesn't support your Nvidia GPU properly, which is why "I have to boot with `nouveau. modeset= 0`, otherwise boot hangs at Plymouth after entering my disk encryption password.". But that doesn't matter too much here since the desktop will be rendered using the Intel GPU instead.
2. i3wm doesn't seem to be using compositing, so tearing and flickering is expected. Maybe you can configure i3wm to enable compositing, or maybe it doesn't support it at all. Either way that is a problem with i3wm only.
Only #2 is the real problem here. If you would like to avoid tearing then I suggest you will need to use a different window manager or desktop environment. Not i3wm.