Right now, the projections have problems showing whether the orbit will even return or not when the object is a great distance from it's sun or whatever it's orbiting. The projections will be much, much more accurate in Ubox3.
you can also use trails and set the trail length to very long, then run the simulation for a while. that should prevent them from seeming to veer off into space.
Yeah, this ^. The projection really only shows what the path would look like at that instant, so if there are nearby objects or it's going close to an object, it can seem like it's going to slingshot out to interstellar space.