I am sorry no one has responded yet to this issue. but it is a pretty complex issue. and I was waiting to see if anyone else had some suggestions for you before I threw in my two cents.

the best thing I can think of is to use the nurbs curve for the ribbon and actually model out a piece for the bow and not make it out of the splines.

as for animating it untying itself my best advice is to experiment. if you cant find a nice way of doing it try and fake it as best as you can.



as far as i know nurbs curves dont like to fold in over them selves like a bow tie would which is why I suggest modeling it as a separate object.