I did it last year too. We started locking threads because people would continue to post in them (and in the case of tickets offered, bombard the OP with private messages). The tickets wanted/offered boards need to be 'working' forums, so that those either with or seeking tickets can find open/active threads quickly. If people want to start a congratulatory 'got my ticket' thread in Tickets Discussion
(like we've had for pre-sale, main sale, and STEP) that's fine by me.
As for the Artists/Stages threads, they're done. They were kind of problematic (mostly spam) before Spark finally launched, and once the collaboration tool became available they became completely redundant. People already can and do use ePlaya to post threads about their camps, stages, or their bad selves - and you're welcome to continue to use ePlaya for that purpose (don't go nuts with multiple threads though, just reply to your original thread with updates). Personally I think that having a separate thread for each project/artist works a little better, as it allows for banter and feedback.