Midi accordion

Hi, I’m totally new to arduino and to midi and have extremely basic understanding of the terms and concepts involved.
However, i’d really appreciate some advice. I’m wondering if it’s possible for me to convert an acoustic accordion to midi using an arduino.
I’ve found a video in which 4 computer keyboard are linked to an arduino uno with two PS/2 ports and outputted into a computer via a midi port. I figured if I could do the same then I could link the accordion keys to the computer keys (mechanically) and make what I want.
I can’t find any PS/2 ports for sake. I assume this is because it’s now more common to use USB inputs.
My specific questions are:
Could I use USB inputs instead of PS/2 inputs into the arduino?
Assuming I managed to do all this and link the keyboards to a computer, could I program each key with a separate tone of my choosing?
Could I link one key to trigger a chord, to replicate the chorded buttons on an acoustic accordion?

Any advice would be gratefully received.
Many thanks,
Sam