Reply to Make Arcade Controller from PC Keyboard

Hi, I was searching for a cheap solution to build a midi controller and I tried to open a pc keyboard to understand how it works.

It seems that is easy to make the arcade buttons work using the controller of the keyboard, and since traktor allows mapping keyboard keys to everything we are good.

Now I have 2 questions for you:

1 - Are you aware of any latency problems with pc keyboard? Witch have least latency, pc keyboard or midi?

2 - I would like to put some endless dented knobs in the controller too. Do you know how they work? May be possible to assign the turning of the knob in one direction to a key and the other direction to other key?

Thank you