so if a game is in open beta ( i no nothin about these O.B and C.B )
and where all testing it out when it is fully released will we have to ReDownload it?
and will our charaters be deleted?

cheers

You don't have to redownload it, and chances are your characters won't be deleted.

Usually only closed beta's are wiped, but of course its just up to the company and whatever they want to do. They may never wipe or they can wipe as much as they want. But the only reason they would wipe is if something got terribly exploited to the point that it screws up everything and makes everyone angry. So there is really a low chance of wipe.