That was an excellent video and shows that most of the controls used in a start-up have absolutely no bearing during combat, they are set-and-forget until it's time to land.
In fact, if you pay attention you'll see that there's a cover over the switches so that the pilot will not push them accidentally, you wouldn't want to turn off your artificial horizon by mistake for example.
This is obviously an instructional video so he goes through the motions slowly. I think that if he wanted, he could have it up and running within less than a minute by simply pushing everything in succession.
As for the warm-up, we can see that most high performance WWII engines reach operating temperatures very fast. The captions said "Wait for 45 degrees Celsius oil temperature before taxi" and in the time required for him to look around the cockpit and confirm that he didn't forget anything, it was already at that temperature.
The rest is stuff that you do while taxiing to the runway, i mean since you're obviously going to s-turn in a taildragger might as well check if your turn indicators work.
I'm off to watch the rest of his videos on the 190
