considering the fact that i (only)use 3dmax for fun, i must warn you that it will take a LONG time for getting confortable with it. this software is used by professional artists and some amateurs (like me), so the price is really high. i didnt have the $ for buying it, and i dont use it professionaly so i got a copy from a friend.
3dsmax is not useless for ofp...for example,when i want to open a highres model (*.3ds file) with o2, i need to cut the number of polygons drasticly before... otherwise o2 crashes.
there's some other's functions i'm still searching, like importing with textures correctly.
but if ur starting a model from the scratch, NO u dont need 3dmax at all.