My personal opinion of what should be done:
1. Only gold that spawns with no character loot assignment still spawns (the gold from a champ's death, for example). Similarly, if two monsters fight without a character's direct intervention, gold will spawn on the corpse (provo has the gold go to the Bard, as Taming does for the Tamer).
2. Gold can still be withdrawn as coinage from the bank, up to 60k
3. Gold balance is for the account on that shard. The Balance can be checked by a "-balance" command that is only visible to the person making the request.
4. Vendors have their price cap removed. NPCs get fixed to where all will allow payment directly from the account.
5. All checks over the minimum normal check amount get converted to bank balance. Those under are left as rares. Add a process that turns checks into "cancelled checks", static items no longer exchangeable for gold, for rare white checks, and checks over 1000 that people want to use as deco. Care, though, would have to be made to make sure the checks don't change color when converted.
6. Houses, in their transfer gump, get the option to specify a price during a transfer, that gets moved from one account to the other on a successful transfer.
7. Money & checks cannot be shard transferred on characters. However, a system would be put into place to allow shard-to-shard transmission of gold on the same account, but with a wait time and percentage fee charged.
8. Transfers between accounts either have to be done in a trade window. The window would have a space added to specify a gold amount. Alternatively (especially if we get an in-game mail system operational), one might be able to set up the shard-to-shard system in 7. to transfer from account to account on the same shard, provided you know the ID number of a character on the destination account (what is displayed in chat).