Is smoking the NON LIT part of my tail light legal?

you have not told us what state your in. all states are different. i've verified the same thing on my truck go to your states government law page and it will tell you the exact specifications for what a police officer will pull you over for. worst case drive down to the local sherrif department with a picture and explain the situation. they will give you advice happily so they don't have to pull you over later for a fix it ticket which is a waste of time.