If you want to disable head tracking, please set the sensitivity to 0.0 on the head tracking page of the ingame menu. There also is enable/disable switch, but that’s borked currently. Do not use it, may lead to one eye showing upside down.
Game profiles can’t be edited in a text editor since they are stored in a database. All relevant user settings can be changed in the ingame menu and are then stored in the database.
If the question is related to settings not being saved, please make sure you have the latest hotfix 16.2.1 from two days ago installed. In the last version there was a stupid glitch that could lead to the database not getting flushed to disk.