I have a lot of experience with making followers do special combat behaviors, so I'll answer - -
Probably. Assuming that part is a dialogue command then yes. I KNOW from a bug I encountered that there are dialogue options for things like follow and other stuff. Someone else mentioned that here too.
Still, assuming I can find any mention of said companion wheel and trace it back to something then we should be able to at least port it to a FOSE plugin. Alternatively, maybe we won't even have to do that (probably will).
The whole 3 states thing though? Oh yeah, that should be easy enough to do with GECK.
That is not a bug for dialogue control - - the control abilities which you see in the Companion Wheel exists in 2 places, that's all. You can use the wheel, or, you can go into dialogue with the follower and change options there.
There's an explanation of how the Companion Wheel works in the first posts of this thread, check there.
The 3 states you describe are not doable unless you are really experienced with follower brains. There is more than meets the eye to it. I happen to have that of experience, and you can expect to see something like this in the near future (couple days I guess). For me it is just porting a small bit of function from my FO3 follower overhaul mod (FO3Phalanx) to this new game. Just some.
Well, that would explain why my companions keep running around gunning everything even though they're on Passive, I suppose:p (I'd still love to be able to switch between three different companion modes - attack any enemy you see, attack only if the player is currently in combat and stop attacking when the player has stopped firing/being fired upon for 10 seconds or so/under no circumstances fire back - but from this I really doubt that'd be possible

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Question: Would it be possible to change the Companion Wheel 'give follower a stimpak' command to 'repair ED-E' or something when used on ED-E? I don't want to give a robot stimpaks in order to heal him.
As far as 3 modes go - - it's possible to do many different things with this. I'm probably going to make a mod which makes a number of them. The behavior of "aggressive" while you are wandering through the wasteland will be toned down just a bit to where it is less of a nuisance. "passive" will require you to take damage before followers will intervene. I've already done these things in the first version game, so it is straightforward for me to put it into NV. Just keep an eye out for that mod I guess, once again it should be in a few days, kinda when I get to it.
Stimpacks actually heal that robot? Interesting. As far as them releasing it that way, there are some gameplay issues with changing that, primarily that repair is expected to be in some way tied to the repair skill of the player. It snowballs a little. In the context of a mod: it's an easy change to require you to have "scrap metal" or similar, and it's also possible to have the HP scale based upon repair.