He who is Mayayana said on Thu, 28 Sep 2017 11:00:52 -0400:

I'd be interested to know of even one free video
editor for Windows that has drawing tools like
line, rectangle, etc, that can be applied on a
per-frame basis, or even to the whole video.
I spent an afternoon exploring at one point and
Avidemux was by far the best option I found.

Hi Mayayana,

I haven't tried what you ask above with Shotcut since I only needed an
assortment of variously sized rectangular blocking boxes on arbitrary
sections of the video, but...

From what I have learned about Shotcut, I think it "should" be pretty easy
to do if you can create the drawing outside of Shotcut in any drawing
editor.

Then all you do is overlay that drawing onto the section of video that you
want to obscure.

Shotcut "says" it can do this, no matter what format the drawing is in
(PNG, BMP, JPG, GIF, etc.).