Zaki I understand your point about not wanting to issue inside the Cosmos Hub namespace.
Since the Hub is already intended to support <namespace, denom> tokens for IBC, here namespace = source zone, I guess it could make sense to incorporate it into the implementation of proposal #5.
This would also support the use-case of bootstrapping new projects, where they they do an initial issuance inside their own namespace on the hub, and then migrate later on to their own zone. The new zone would then have a genesis state stating that X amount of its tokens are already on the Hub.
For our own part, e-money is fine to issue inside a namespace as well, we have no speciel preference for it happening under cosmos ns.
How would you feel if gov was required to register a new namespace, but creation of new tokens below this namespace is unrestricted? I think could work nicely for an implementation for proposal #5.
PS. Not a big fan of the per-account namespace, account identifiers does not seem like a natural namespace. Namespace to me means something more than an account.