So levels and ilvl should be account wide. Swap your race and class and faction in rested zones. Alright man.
Make transmog, barber, auctioneer, bank, guild bank, raid vendors, pvp vendors, mailbox, profession trainer, and great vault all the same NPC, an ethereal you can summon with a toy.
Roleplay *always* stands in the way of gameplay. Everybody draws a line between convenience and immersion somewhere. The question in this post, broadly, is this: Where is yours?