For option 1 that would most likely come with a big nerf to all the money gained (like the cofee biscuits leve already nerfed in the past), and that would just make the players not caring about the achievements angry. The problem being that they are surely more numerous than the players wanting long term achievements.

Options 2 and 3 are awful. "Oh, you did spend many years dedicating yourself to the game to get these achievements ? Well, now we are gonna change them so that people cheating with boting add-ons can complete them in less than a week being afk, please understand and don't be angry". Kinda shows how hard being a good game designer is, and how "wait, if i do that how will players try to abuse it ?" is an important question to answer before making changes to a game, if you don't want to end with even more threads like When will SE acknowledge there is a BIG cheating problem? on the official forums.