I would like to propose that you be able to add your characters like NPC vendors to your house (the character you are currently logged in as would disappear). Then treat the inventories of those characters like they were a bank, allowing you to put things into their inventory from your current character and take them back out again. This would not only make the house feel less empty of people, but streamline the transfer of items between characters, rather than forcing you to go through lengthy logins just to swap between them.