Easiest way to move any Windows application beyond very simple self-contained ones that don't put things in the registry etc. is to uninstall and reinstall.
Otherwise as a minimum you need to go through the registry amending every entry to do with that software and its hangers-on and dependencies, and relevant contents in the (hidden) c:/programme data folder and some of the stuff in hidden folders in your user directory might need moving or otherwise adjusting as well. Windows basically expects applications to be in certain locations, and moving them once installed is much more complicated than simply installing them elsewhere. Even then putting 64 bit applications where Windows expects 32 bit ones can cause problems.
Even if Sonar itself is moved it will still be accessing the C drive programs data etc. Some of the plugins also have data (e.g. samples) on the C drive and will be accessing it from there.
If you have a single SSD I'd suggest reinstaiiling from scratch and putting Windows and all applications on it. That will give you the biggest speed boost regarding loading applications etc. Unless you use huge sample libraries you can probably get away with putting samples on it as well so long as you don't also use that SSD as the audio spooling drive. SSDs are fast and have very low random access times so don't tend to cause the disk thrashing that having Windows apps and samples on the same drive does with HDDs.