What about video editing? I mean, I can live with Audacity for my basic needs, but I can't find anything simple as iMovie. Or should I just bite the bullet and learn Blender? Does it have preset screen transitions and stuff like that?
Blender's Video Sequence Editor just has a couple of quirks to get past. It is not deeply mysterious.
Like: the VSE viewer and the Image viewer are similar but distinct; that can be confusing. And OpenGL acceleration on a Scene strip shows a 3D model rendition that is not (in general) the same as the rendered output of the Scene.
If you want to get fancy with the compositor + VSE, again there are just a couple of quirks but the learning curve is merely steep, not long.
Have you tried DaVinci Resolve? Last I checked it had a native Linux version. Unfortunately I don't think the Linux version is available for free (unlike the Windows and Mac versions).