You can't accidentally become root. You can only issue a command with
root powers if you use sudo on the command line, or a graphical system
administration utility asks for your password in order to grant you root
powers.

You can't make any system changes without root privileges. Which means,
you can't be removed from the administrative group and still be allowed
to make any changes on the system, including adding, removing or
updating software packages.

If you simply log in and do your work, browse the web, read/answer
emails etc, you are not using any root privileges and won't be unless
you do something that results in your being asked to enter your password
on the local system as part of the system administration authorization
process.