Maybe you should change the topic of your game: CATCH THE RUBBERTREE!!!

ph_settype "cylinder-hulltype" don't work. Only poly and box work.
Try to keep the polycount low. (Or hull the tree in a invisible lowpoly-model, animate this one and connect the origin tree by application)
Try
phent_setelasticity ( entity, var bounciness, var minimumSpeed );It is responsible for the bounciness. See manual for more details...
EDIT: Have you attached a script (action) to the tree?
Would you show it? - The distance/speed in the video is very strange!
mercuryus