Pressed for time at the moment, but re this...

the Taliban probably said something like... "if we see poppies growing we will get the farmers to first destroy their crop then we will shoot them." Its all about the KISS principle... keep it simple and unambiguous and let the ANA enforce it. Life is cheap in Afghanistan.
What makes you think the ANA or the Afghan government have any interest at all in reducing opium production? Aren't they sharing the profits from opium production?

The Taliban were able to eliminate poppy production because they governed the country and there were no limits on the amount or nature of force they were able to apply to do whatever they wanted to do.

The US doesn't want to govern Afghanistan and is not willing to run around shooting people who grow poppies. The Afghan government and army aren't going to shoot people who grow poppies because they get some of the money the poppies bring in. That makes a plan to eradicate poppies by shooting those who grow them a bit fanciful, because neither we nor the Afghan government/army are willing to do the shooting.