If you want to completely restart (no profiles, no plugins) quickly, you'll only need to do two things (after you shut VoiceAttack down) -
If you want to remove all plugins (like Vaicom), you'll want to delete everything inside the Apps directory (all folders). This is usually C:\Program Files (x86)\VoiceAttack\Apps
To reset all of your profiles, you can simply either delete or rename your VoiceAttack.dat file. This is usually located in C:\Users\YOUR USER NAME\AppData\Roaming\VoiceAttack You may have to enable hidden files and folders if you cannot get to this folder. Another option would be to add a new, empty profile and then delete all the other profiles in your setup other than the new one.
Hope that helps!