I don't think "Convoluted path through time" is a sufficient criteria for a Juju. If it's there, then it's a good sign for somethings Juju-ness, and it may well be necessary, but just because it is there, doesn't mean the thing is a Juju.

People have different criteria for "convoluted", anyway. From my point of view, the Bunny was perfectly linear:

Created and used for Con Air, brought by Dave for John, given to Baby Rose as gift, repaired by Rose, given to John as birthday present, given to Baby Jade, repaired again, Appearified to B2 by Jake, upgraded into Uberbunny, returned to B1, sent to John, lost in car, found by AR, used by Jack to dethrone Black Queen, given to John, shenanigans on the battlefield, sent to Derse, destroyed in Green Sun explosion.

Perfectly straightforward.

Cal, on the other hand, inspires his own creation. (He's created from Dave's subconscious fear of Cal.) It's bad for the same reason Future You isn't stepping out of a time machine to give yourself plans for that same time machine right now. It's a proper paradox.