I looked at that series of drills, Murienn.
Wow. I understand the slow riding and track stand (though I cannot track stand), but I seriously doubt I could ever do any of the others, without killing myself. I feel OK that I can (sometimes) grab my water bottle and drink while riding. I am not willing to risk crashing on my old lady bones to do anything else. I still can't take my right hand off the bar easily, but I do, to signal.
Yesterday, I hit some kind of can in the road while riding. I had slowed, to let 2 people who were crossing the street from the bike trail pass, but I must have been going about 15. I started to wobble, but my skills are improved enough that I could come out of it unscathed. I was more worried about my tires.