PlaceActorAtMe may be of some use to you for the summoning. As far as reversing the sprint shout, that's pretty much Impossible as It's distance, speed, etc. are based on the animation for the shout and nothing actually changeable in the CK. I'm not sure of any script that could give a similar effect. Moveto, KeepOffsetFromActor, or PushActorAway might be of some use to you.