Concerning Vimium, there is the Vimium C version that seems to be a bit faster.
On macOS there is a similar software (don’t remember its name) to use a Vimium like feature on your whole desktop.
I'll give this one a go to see if this helps me touch less my mouse
Vimium and other current options lead to quite some friction, as Firefox disables plugins on many scenarios, such as a new empty page.
Hence, you often find yourself in a situation where you have to think whether Vimium is active and you can use Vim-like shortcuts, or you need to fallback to the Firefox UI.
Tridactyl works around this by setting a global keybind ( Ctrl - , ) that either pulls focus back to itself or, if it's not allowed on that page, kicks you to a tab it can control