what is the little black button that the clutch pedal presses down on when the clutch is fully released? because i'm planning to adjust the height of the clutch but the height that i want is not pressing down on the black button, so is it ok to not let the clutch press that black button?

 

the G35 may be slightly different, but this may help.
https://g35driver.com/forums/tech-07...-specific.html

 

It's used by the cruise control. If you're cruise is engaged and you press on the clutch, it will disengage the cruise just like hitting the brake pedal will. There is some adjustment in the switch, but follow InTgr8r's link to do it the right way.