Reply to Building a custom controller (some How-To's)

Hi, I'm a regular reader of DJtt and you got me to get into controllerism at last I'm an amateur mixer and use CDj players for mixing my tracks, but i have worked a lot with traktor 2 and 3 before I bought the CDj players.

So now I'm trying to build a small custom controller and have been reading several sites about midi, hid and controllerism and I'm quite lost..

The controller I want to build consists of deck control buttons (cue, play, pause, pitch bend...), volume faders and EQ knobs so I can control traktor.

I have some experience programming PIC microcontrollers (with C language) and that's why I didn't want to buy any Arduino or U-HID board and build something similar myself, connect the sensors that I need and send the data out ready to be interpreted by the software.

1st question:
What data format should my controller deliver to the pc? MIDI? HID?

2nd question:
I wanted to send the data for traktor via USB, is it possible??? Do i need to change the data format because of that or the USB transmission acts only as a channel where MIDI data passes through???

3rd question:
What does the controller have to do (in terms of communication) when connected to the pc so that the pc recognizes the controller as what i want it to be recognized (a MIDI controller)???

I'd apprecciate if someone could help out pointing me in some direction.
Good vibes from PT