...for some reason, a lot of non car people are sharing this and saying its great?

why is the center of that 440 that color?

That used to be the "hot" trick, painting the valley red, aided oil drainback they said.

To seal any residual gunk and debris from hot tanking and grinding the slag off of the lifter valley getting into the oil and supposedly aids oil return a little.
I can't remember the proper name of that sealer now but is has been used for a lot of years to do that I'm going to say it is a Smokey Yunick and Grumpy Jekins trick originally, I don't have a clue who they pick that up from
I use Rust Oleum Damp Proof red primer to seal my motors, have for years and years with no issues

Thanks, now I know This is my 440 block done by Koffel's Place II (just down the road from me), looks similar to that coating.

I guess I should have watched the first minute of the video as he mentions Glyptal (duh)

Glyptal Red Brush On
Seals uneven surfaces in engine
castings to improve oil circulation

Why does the cam gear look bent when he rotates it?

Say that also (at the 11:30-ish point) but then looked closely and I think the attachment bolt is missing and he was using the same cam gear to turn both the old and new cam as he was cleaning and just put it on slightly or just enough to turn them?

That is the rust Oleum primer