I'm definitely an amateur, but I strive to get good results.  Sometimes I wonder if our photos are getting too good and then we'll botch a set and then I don't worry about it for a while    

  If you watch any of my videos or the clips that I upload with updates,  you can tell I'm totally an amateur.  Nothing is scripted and we try to be humorous most of the time.
What makes a pro?  Regardless of how slick or not your material looks, if you can pay all the bills with your adult income and that's all your doing then I think you're a pro.  Every charm I've ever talked to says their charms income supplements another job, gives them some mad money has a homemaker (that's me), or beefs up their retirement.  There are a few models here that knock out amazing set after amazing set but they still look like the girl next store.  I've shot with 5 different charms so far and we're all so much alike.  Charms for all of us is a fun way to turn our sexy personalities and exhibitionism into a little cash.
As for labels, I think the industry tries to make it easy for men and woman to quickly find the type of model  or theme they're looking for, but most of us fit into a few of the main categories.    I consider myself a BBW, but I also fit the MILF, BUSTY, and PAWG categories.   As for themes, everyone I know tries to hit all the ones they feel comfortable shooting.