The choke plate is at the top of the carb, no need to look down the bore and risk singeing your face.
Your engine must be great the way it fires up like that. However, I would never rev a cold engine like in your video. In my wife's country of Indonesia, they start a cold engine, rev it up to 5000 rpm cold, then race up and down the street to "warm it up". Probably trying to make the gods happy. Makes me cringe just imagining the damage (spun bearings). At least they are on the equator and not in the frozen north.
I also suspect oil getting into the intake. The typical symptom is blue smoke after idling a long time at a stop light, since that is max vacuum which sucks oil past the guides. My 82 Aries was an absolute mosquito fogger after sitting at a certain long stop light which faced uphill. Turned out I had installed the plastic PCV box onto the valve cover wrong and it got oil drops into the PCV snorkel, as they slung upward off the camshaft. I pointed the snorkel down, which seemed intuitive, but was wrong. I finally noticed the slot in the snorkel elbow and thought "ah hah, a drain slot". The snorkel was supposed to point up to capture air from the top of the cover. Later read about that in a book. Check your PCV valve. Some aftermarket valve covers don't have a baffle to stop oil from getting to the PCV (can't tell what you have from the video).
Worst-case, it is the valve stem seals, but you can change those with the engine in the car, but a little tricky, so read up. There used to be a fix-it kit with umbrella seals and glue that didn't require removing the springs (just unbolt rocker shaft). My dad used that to fix my sister's 65 Mustang six cyl long ago.
