I'm think Comfy intends for reading the lessons and watching the videos to count as learning, but I don't remember where I got this impression. I'm on Lesson 5 and I have been counting my time for reading and watching the instructional material as learning in addition to actually doing the exercises. In a way I think that the time spent playing is more important than the time spent learning. The point of the 50% Rule is to get you to actually draw the stuff you want to draw without fear or hesitation, even if it turns out bad; after all I'd say it's better to enjoy drawing and be bad at it, than to have all the skill in the world and be paralyzed by fear of making a mistake (being afraid to ruin my art has paralyzed me many times). By counting my time reviewing the instructional material as learning, I am increasing the time I have to spend playing. It's during play that you actually apply the lesson material in real-life drawing situations and see how what you've been learning is affecting your skills.

Only my opinion, but I'd say there is literally nothing that counts less than reading about how to draw instead of actually drawing. That being said I do tend to cheat a bit by counting it as preparatory work, along the lines of gathering supplies etc, and not part of my practice session or the 50% rule.

Personally, I read it as physically practicing rather than reading the instructions being a part of the 50%. But then you have to consider that you'll possibly be referring back to the reading material whilst you're practicing, especially if it's something on the longer, more complex side. So it really depends on how strict you want to be with yourself.

I alternate days for my 50%, so I practice one day and try to draw for fun for the other day. So the timing is more lenient, but that's mainly because I don't have time to do both each day or I'd end up with nothing to show for it. In your situation, I would probably not count the initial reading as a part of your 50%, especially as some of the later exercises have forty-minutes to an hour long videos alongside them.

Personally it feels like so much of learning these skills is building up muscle memory on various shapes and a mental book of what did and didn't work so if you arne't putting pen to paper you aren't getting the most out of that time. I'd read on the side, but try to still put in the full 50% towards building the hand-eye-minds eye coordination.