I don't think they are needed, the aluminum spur mount will take some of the extra flex away which may make a difference. I haven't seen a setup sheet using the third hole on the steering rack. Finally the metal side pods definitely aren't a necessity.
If you do have spare cash I'd certainly recommend the D-Joints they quieten thing down a little and you don't take as much out of your lipos as they are way more efficient. An RW spur is a good buy too.
