Is it possible to set a multi-key combination for a single keybind (Shift+Up Arrow)? If not, could this be added?
I can't get the hang of vi keys and would like to setup an alternative for movement.
It's not currently possible. I will consider adding such an option, but don't expect it too soon, as it's going to take some thought to implement.
There's also another option for diagonal movement aside from rebinding keys: you can point at the target in examination mode and then press the "confirm target" key (default Z, enter, space). Try it, maybe you'll like it more.