Well, it gets a little complicated, but there's three things I need to do within my application:
1) reposition a body to an arbitrary location without it interacting with the rest of the physics
2) move a body an arbitrary distance so that it does interact with the physics (this could be extented to a version of #1 that interacts with the physics - moving a large distance to the new point instead of just changing the position manually)
3) animate a body while still keeping it in line with the physics
#3 is really just an extension of #2
It looks like for #1 the only option is to manually change the position? That should be fine as it won't happen over and over again at once.
As I see it, there are two options for #2 and #3. Either use cpBodySlew to move the body, making sure to zero the velocity when done, or attach a "middle man" body to each real body by a joint, without adding a shape for the middle man. The middle man can then be used to move the real body in either my syncing system or the animation system, each having only to set the middle man body position, the real body following.
Will either of these methods, cpBodySlew or a middle man body, work for my purposes? If so, is there a reason to prefer one over another?
Am I missing something here? I'd really appreciate some help with this on a design level, I'm still getting acquainted with chipmunk.