3) Use a FMPro client as "robot" like someone do it for print or save as PDF...
There is no script step for editing custom value list, so this may be a bit harder to make.
(2) is the answer. It is not that much of a hardship to make and will make for a better, more flexible solution in the end.
I thought I may have to do that... It will make this project a fair bit longer. Basically this application is a biiiiiiiig list of different of drop downs so it will significantly increase the project time.
I will need a different layout (or pop up) for each drop down I want to edit.