What occupational complaints do service workers have and would joining a union help resolve these issues?

Didn't go to college, I was a worker. I would guess:
Not Getting paid for overtime.
No Breaks
Unsafe conditions, and none or lacking Safety Gear.
Paying for your job.
Employer not providing Data Safety Sheets on hazardous materials.
Sex, Age, Race, Political, Height, Weight Descrimination.
Dealing with rude customers.

I'm not real sure what your asking, can you give a little more detail to this question? Are you asking if joining a union will resolve basic work place complaints?

That's true I guess it would be hard to determine until you see orhear the problem at hand yes this was helpful

I like that