I'd have to agree with Bob. If you are doing motion graphics I'd say you absolutely need the full mograph set, including Voronoi Fracture.
Likewise the dynamics and softbody tags, which I find myself relying on quite a lot for all sorts of setups.
I think it might also be a mistake to be assuming that XP cloth will be totally fine for every cloth-related need. For character cloth, you really do need something like Marvelous Designer, but for other cloth work you might find it useful to have some cloth functionality built in.
The other things you have mentioned I would say are less of an omission / problem in day-to-day work, and as long as you have RS and XP you do have your rendering and particle bases covered.
Sculpting-wise, Zbrush is a good idea if you do it all the time, and know that software well. However sculpting in Cinema is rather quicker and more intuitive if you are not already a ZB expert !
CBR