Despite their PITA copy protection, that fact is that Waves plugins are an incredible value that should be the first bundle you buy. They sound amazing and work well in almost every host.
The WUP is not required. I am still using V4 with no problems. If you look at the WUP in a less cynical way, it's a pretty cost effective way to make sure you always have the latest version. BEWARE - latest isn't always the greatest
The Wavearts Master Restoration is incredible if you have such a need.
In my opinion Waves + UAD2 would be all you really need, but you can add a few special things as needed.
~Jay