So how about this approach:
1. All players will be given Opportunist and the mod will track when this has been done for each player.
2. If a player later removes Opportunist, the mod will perform one of the following:
2a. Reduce the number of available talent points by 1.
or
2b. Force the player to take Opportunist before any additional talents as to ensure no free talent point stealing. I'll display some text to indicate as much.
Does that make sense?
That makes sense, yes. It seems like a good approach. You can take all the credit for the mod.
I would hopefully like to see the project at some point, just to see how it looks in the editor so I can understand how it was done. The closest thing I can find in the editor is the Script Editor, and the format used in the provided scripts seems a little different than the format from the \Goals\mod_text_files.