Also, when closed beta starts, you will more than likely need a key of some sorts. However, there is a chance that what happened with Kitsu Saga will happen here.
What am I talking about you ask? When Kitsu Saga Closed Beta started, people were able to freely sign-up for closed beta and immediately log into the game. This was not supposed to happen as Venom and other GMs / Admins said during that time. Due to this, over 2k people joined the Closed Beta of Kitsu Saga, but not before the GMs shut down and fixed the CBT sign-ups, forcing many newbies to wait, and start posting complaint threads. (Also, some users had their characters and login access to Kitsu Saga revoked if they were late enough to the party.)
When open beta came, they re-opened everyone to be able to join, though characters were wiped of course.
Yes, characters will be wiped from CBT to Open. You will also get free AP to use on the CBT Item mall. Any CBT Item mall items will be also deleted along with your CBT character. (Just to test if this was true, I purchased item mall items, left them in the item mall redemption box so the server would think they were attached to the account and not the characters. However, all of it was removed when Open came.)