Here's what I'd do.
First, buy a new, smaller HD for the System drive. 1TB is overkill, as you don't want anything on that drive but the OS and Programs.
C: 256GB - OS/Programs
D: 1TB - Projects/Scratch (including music and image files in a project folder)
E: 1TB - Media (nothing but the captured video files)
F: 1TB - Exports
G: 1TB - Archive (Project folders from D, but not including the video, which can always be recaptured if need be.)
This will spread the load out fairly well.