Wooting has options for emulating controller inputs, like joystick axis and triggers. The default is a binary toggle for which the actuation can be changed, though. Makes sense in regard to typing and such.

I've never tried one, but I tdid look at them last time I got a new kb (2 years ago?). IIRC you can do pressure sensitivity, but meaningfully mapping that to game/software controls is often difficult. You can also adjust the trigger point if you're using "standard" mode, and I think you can even set a different action for passing the trigger point and bottoming out the key.

If you want to go overboard, you can even create something akin to a macro by assigning multiple actions to the same key, so that a single keypress registers a different action when you’ve pressed half-way down, as you bottom out and when the switch pushes the keycap up again — and maybe another one somewhere in-between. I haven’t quite found a personal use case for this yet, but somebody surely will.

From the article. Cool stuff!
I'll be over here with my 1/64 keyboard.

All that yes. The Wooting One (original that uses IR light) let you use buttons to simulate controller axes, change how hard you need to press to activate, and add second functions to keys. It was an interesting idea but I found the gaming part the original keyboard to be only usable in a limited set of games as it’s not as sensitive as a controller stick, and as a keyboard it wasn’t great either. Hopefully V1 problems, I know they had through another version of the IR keyboard, and then came out with the Hall effect keyboard. I like the idea but never could get used to it, and when the spacebar was loose I retired it after fixing it.

Sort of in a way, yes, if you count there is some increasing pressure from the spring. But in reality, no, it is really based on the travel distance that can be adjusted. But you raise an interesting point for a future innovation, being more around actual pressure/resistance per key setting.