I see two issues - no ND filter, so you're going to see a fine grained flicker no matter what because the individual frames are too sharp.
The second problem is converting your original 24 fps video to 30 fps. This means youtube has to come with an additional 6 frames of data per second, which it does by doubling every fourth frame, which adds another level of jerkiness. You see this a lot when a movie is shown on TV - drives me nuts but no one else seems to notice it, lol.
So - if the flicker bugs you, I have two suggestions. One is to use an ND filter and get your shutter speed to be 1/2N where N is the frame rate. So at 30 frames per second that would be 1/60 sec. The second is to try recording 1080p or 720p at 60 fps. You give up some pixels but the smoothness will be incredible.