Pressure button is probably an eleminator button. These are little rubber "buttons" with a hole in the middle of them and are threaded onto your string. You use these eleminator buttons to provide a cushion between your release and your arrows nock. They help eleminate some nock pinch and reduce wear on your nocks from your release. You don't tune hem. They are only there to act as a cushion.



The brace height is not adjustable unless you change your draw weight. As you increase the draw weight on a bow the brace height will be shortened slightly. Just opposite if you decrease the draw weight. However you can't adjust it in the way that you are refering to and still have a properly tuned bow. It is what it is.



Yes you can open and retighten a brass nock on a string but use nocking poiers and not something like a screwdriver or a butter knife. I would strongly reccomend however that you install a new nock once you get it where you want it.

In all honesty I reccomend that you use a string loop rather than any brass nocks. There are sooooo many advantages to using a string loop over a conventional brass nock.