screen capture

OBS (same as is popular on Windows).

video editing, audio extraction and editing

I basically never do that sort of thing, but if I needed to I’d start out with Kdenlive and Audacity, respectively.

See also:

itsfoss.com/best-video-editing-software-linux/

itsfoss.com/best-audio-editors-linux/

disc imaging

For a task that basic, most of the time I just use dd.

photo editing

GIMP and/or Krita.