[RichardJ]

The valve inside the air cleaner operates with heat, to open the snorkel door for cooler air to enter, after the engine warms up.
The vacuum port for the Thermostatic Air Cleaner (Thermac) should be capped or plugged with the air cleaner off and the engine running. You are providing a vacuum leak the upsets idle mixture and idle speed.

You have three hoses on the charcoal canister, visible in your video. One hose goes out of sight under the battery.
Does the end of that hose have the nipple that is missing from the carb?

The choke rod coming out of the Bi-metal Choke Stove on the exhaust manifold is working in your video.
The choke has two functions.
When you step on the throttle of a cold engine the high-speed idle is set along with the choke. I.E. together.
Heat turns off the choke (opens the choke valve) , independent of the high-speed idle. By once again stepping on the throttle, the high-speed idle mechanism is released. The rod on the back side of the carb is connected to a high-speed idle cam.

Your high-speed idle mechanism is obviously not working properly.

Some carbs have a idle speed screw and a separate high-speed idle screw. Yours may not.

Fix the missing large nipple on the carb, cap the lower vacuum port, warm the engine up and adjust the idle speed down to a reasonable rpm. At that point see what you need to do to get a correct high-speed idle.

That missing nipple would certainly have allowed dirt and water to get into the float bowl so you may need to rebuild the carb. I am not certain if or how much that open hose would have upset the vacuum in the charcoal canister.