Does choosing "suicide" from the pause menu make your team lose a ticket?
Solution 1:
Suiciding in-game equals dying by getting shot or blown up, so, yes, your team will lose a ticket every time you do that.
My advice: Play along defensively, and switch to another class by picking up a team mate's equipment.
Solution 2:
It counts as a ticket UNLESS you do it during the pre round countdown. If you suicide to change class at the very beginning of the game you are in the clear.