How to change not visible Hotkeys?

Hey devs,

I want to know how I can change hotkeys that are not visible under the controlls menu.

Since for example my push2talk for teamspeak, is "c",

but "c" ingame a does lot of stuff, also its not under controlls, so i can´t change it.

It switches me to character selection when i´m dead, which means I can´t get revived.

It mutes/unmutes players if i´m watching on the score screen etc.

Lots functions I don´t want.

But there is no visible way to change it.

Can you make all hotkeys changeable or tell me where a .cfg is, so I can change it, its pretty annoying when I play with friends.