yeh what u said have a bag of furniture which can be accessed by the people who u give the right too. they should be able to place it on ur home or take things back into the bag but not delete or anythingZos will never give someone else access to your inventory bank or character inventory. It can cause to many issues and is probably not easy to do.
What Zos should do is create a furniture bag that stores all bound furniture that is not placed in a home. it is a great idea because a player with overflowing inventory is not likely to buy crown furniture packs if they have to trash some existing furniture. So it is a win/win for everyone.
Then Zos might be able to give access to those set as decorators. However, it could still be to complicated for Zos to want to attempt. But that is a different story as this idea would not create the issues of granting access to bank or character inventory.
Perhaps a way to do this is to toggle in-house chests to be accessible using a similar interface as the housing permissions screen.
This way, chests could be private, open to named individuals, or effectively public based on your home access parameters.
This would also be pretty cool for guild halls.