I've only gone to one pole convention this past June. It was an absolute blast! However, I went to one workshop and the interest for most in the class was to learn something advanced. Even though it was fun to meet and be in a class with Felix Cane, what she taught was way too advanced for most in the class. The few advanced gals learned something which is good.
Also when I was trying to decide which workshop(s) to take, I emailed pole convention coordinator with same question about level because I'm not that advanced. She also mentioned to me the pro's usually tend to teach their signature spin/trick that can fall on the advanced level. So I didn't sign up for any. The Felix Cane workshop was one of the free ones. Read the description of workshops, hopefully it will give idea of level.
As far as sharing poles, at LA pole convention, the free workshops allowed many to attend, thus sharing, there were 3 to a pole at the one I went to. The other paid workshops did have maximum for one person to a pole. I don't know if all conventions do the same thing. Usually the workshop description specifies how much space in a workshop.
That being said, it was a blast going with group of gals, meeting the pro's, taking pics and especially the showcases/performances!! I would go again if I could. I'm going to play it by ear about going to Vegas Expo.