well that was different. Never had a video presentation of problems but...it does help.
1. Clutch arm position: There should be a small amount, hardly any, slack in the cable when the clutch is engaged. (handlebar lever not squeezed) The actual position of the clutch arm on the engine is not important. You want it so the cable just starts to move it as you squeeze the lever.
2. Clutch lever and handlebar:Not sure here. It appears as if the lever doesn't have enough throw to disengage the clutch as it would normally. Without actually feeling the lever and checking clutch engagement and disengagement its hard to identify your problem. Is that the lever that came with your kit? Is there too much slack in the cable?
3. Spark plug: As I told your earlier. It needs to be torqued to about 10 to 12 foot pounds to seat the gasket and keep it tight. The color looks as if your fuel to air mixture is a little lean. Unusual especially with the 'C' clip on the 2nd notch. These engines typically run rich. You're shooting for a chocolate brown color, not gray or white. That also depends on how much running time on the plug. It might just be that you have not run it enough to get an accurate plug color reading.
4. Oil: Your choice of oil is fine. if I recall you said you were running a 32:1 mix. That's a little oil lean for initial breakin but not dangerously so. You'll be good.
Check your clutch cable run for kinks or sharp bends. These will/can cause a hard to pull clutch. It can also mess up the clutch cable's ability to pull the clutch arm in correctly; which could add to that handlebar lever situation. You might try lubricating the cable with light oil or graphite. That often helps reduce the friction.
Hope some of this helped you. And thanks for the nice vid. Oh, and Pablo is right...sounds normal to me.
Tom