Hi every one

I'm planning to make a one handed gamepad to play along with a mouse for PC, so I can enjoy analog stick to move and mouse to aim. Best way to do so is making the gamepad recognized as a keyboard, so all components work the same, and keyboards + mouse is compatible with any game, witch analog gamepads + mouse is not because using HID (or other joystick layers) with raw input is messy and not supported by most games.

So far my plan was to canibilize a gamepad into a one handed pad and make it recognized as keyboard through Antimicro, but finding Teensy on the way I wonder if it wouldn't be a better option because...
A- Teensy form factor is way easier to work with for this project.
B- If I'm not wrong I could get three move options with the analog : deadzone, walk (direction + modifier) and run (direction and no modifier), witch is better than having to use a button to apply the modifier to walk.
C- I could avoid any additional software layer, and the less the better.
D- It's quite exciting, it makes years I'm interested by Arduino but had no needed project to have the will to get into it.

Could you please tell me if this is right and would work as I would like (especially about the walk / run thing) ?
If so witch Teensy version would work the best (just need 1 stick and 6 to 8 buttons) ?

Thanks a lot by advance, best regards !