I haven't played SCH, only a bit of Arcanist so I can't put TOO much input to it... but, just put Heel next to Stay/Place o.o And then jab the when you're about to run off.

I don't agree with Sanguisio's wording, at all - but yeah, I don't think it would be too difficult x.x;; Pretty much as ItaruKarin said.
I think they didn't auto-heel the summons so that you could get to the max range without it suddenly abandoning it's post (though, that does not make a whole lot of sense) - or possibly as a mechanic of distraction on a mob for the player to run and escape while the summon tanks/hits the monsters (I've done this with my Carbie, before, if not as happy accidents x.x). But I could be entirely wrong on that.
I don't know the faeries ranges but my Carbie would only poof after I had quite a bit of distance from it.