I'm assuming you mean the homeschool conventions. It will might vary from state to state, but in general.... No, they are not considered "professional". Many of the presenters aren't "professional"...ie: they have no "qualifications" other than experience. I wasn't able to maintain my certification, btw.
I wish. Homeschool conventions are much more interesting than PDE classes for educators. I take most of mine online for free through our Dept. of Ed. They're painful to sit through, but they're free. Also, our museum of local history offers free PDE classes that are very interesting and of benefit to me as a homeschooler. I can't get many hours that way, but the few I get are enjoyable. I try to keep my up just because it makes my life easier to be able to "tutor" my children rather than "homeschool".
FREE? If they had that in Ohio, I'd do it! Here, if you take a workshop-style class (as opposed to a college class), you have to pay EXTRA to the state to get your CEU's! (Or that's how it use to be!) I remember one workshop I took on ADD/ADHD for "parents and professionals". You had the cost, and then the additional fee for the teachers/nurses who wanted their CEU's.