Removing or extending the 21M limit would be a disaster, it's the finite supply of this digital cash that makes it useful as money.

Allowing for the currency to be further divided would solve that issue. No one loses the value of any of their currency held(devaluation or debasing), while at the same time being able to break off smaller pieces of a ฿ to trade.

Besides, the whole point is that there is no (central)control over the supply, this would allow it to be extinguished by governments or abused by a central authority (like today's central banks & governments)

I am wondering Satoshi, what would be the technical difficulty of implementing  ฿ as 0.000(or more zeroes) instead of 0.00?

This is not a request since there is no need for it yet, but may wish to acommadate a larger user base in the future.