Many years as a flight attendant here...
Bag issues are as simple as popping your head in the FD and saying "Hey guys we're gate-checking a lot of bags back here it's going to be a minute," and an unruly passenger is a definite call the FD immediately to keep them in the loop.
It's effective CRM. My old airline, BrandX, had a 1-4 level classification process for unruly pax, and anything over a 1 was a mandatory inflight irregularity report after the incident, and immediately notifying the pilots. They broke out like this:
1: Not very nice, occasional profanity
2: Verbal abuse, mo
