I think the worst analogy of the Bitcoin system is the "bitcoin" part. It leads to all sorts of misunderstandings, concerns about divisibility being the most common one. It took me some time to understand that there is nothing analogous to coins in the system and bitcoins are actually historical transactions. However, the user never has to know how it works, so it's OK.

Compared to that, "wallet" is actually a pretty good one, and I think it's the reason why the coin analogy was appropriate in the first place. You have your cash stored in your wallet, when you spend it it's gone, when you lose your wallet it's gone. It's harder even to grasp, for the non-technical user, that there aren't actual bitcoins stored there. If you get rid of the wallet analogy, you would have to change nomenclature altogether, starting with "bitcoin".

EDIT: By the way, synchronizing wallets might not ever be an easy/useful thing to do. Being able to use the same key simultaneously from different nodes is a bad idea. You would probably want to transfer your wallet, or split the money in it, which are still good analogies.