OS4 Sams can use Blender to do video editing, which for me it is a bit awkward and far fetched for a 3D tool, which is not the friendliest of all.
On Classics, you can do much easier and better jobs if you have the required hardware and sofware combinations:
FrameMachine + Framemachine software
Vlab Motion + Tocatta + Movieshop 4.x
Newtek Flyer + Flyer software
TBCIV + PAR + Sunrize soundcard
Broadcaster Elite + Producer 2.1
Mediator + BT8x8 TV turner card + VHI Studio
If I had to choose a setup for video editing on Amiga, I would go for the Vlab Motion/Tocata + Movieshop 4.x setup.