People tend to use the word account differently. For my purposes, there is a bnet account (Email), then wow licenses (wow1, wow2, etc) on your bnet account.
Transfers were disabled between bnet accounts, but you can still transfer between licenses on the same bnet account. You might get prompted to rename if both characters with the same name are on the same server.
If you delete or rename a character over level 30 I believe, the name will be locked to you for a varying amount of time. I thought it was license based, but could be bnet based. So if you transfer and are asked to rename, but you know the character is deleted, try reusing the name.