I've been reading Volume 3 this year, and there are a few places where CM touches on these issues.
This chapter made me stop and think about *which* activities we were choosing. As a result of reading it, I firmed up my inclination to drop ballet. We now do taekwondo as a whole family, all together in class (mom and dad too). I will make sure each child has some team sports experience, but we're going to focus on taekwondo and orienteering, both of which teach life skills, can be done throughout your life, and involve our whole family together. (This does not mean you should choose these activities. I'm just showing how we thought through this.) We also do 4-H, which all the children from kindergarten through the end of high school can participate in, and in which we parents can be very involved. 4-H allows us to incorporate many valuable life skills, plus the children get experience managing the meetings themselves. (CM talks about the importance of the self-management aspect somewhere, but I can't now remember where. I think it was probably early in Volume 3.)
In this chapter CM makes plain that lessons are as nothing compared to real, meaningful experiences. The meaningful experiences need to come first and take precedence over structured activities or lessons.
<<And here let me say a word as to the 'advantages' (?) which London offers in the way of masters and special classes. I think it is most often the still pool which the angel comes down to trouble: a steady unruffled course of work without so-called advantages lends itself best to that 'troubling' of the angel––the striking upon us of what Coleridge calls 'the Captain Idea,' which initiates a tie of affinity.>>
What I took from this quote is that children need peace and quiet, they need steady work, not a frantic grind of running from one appointment to another.
So I look for what we can make a part of our home life. I look for what we can make a part of our family experience. I look for what doesn't leave us exhausted and frazzled. I look for what can be made to work over a wide stretch of ages, so my children can all participate together rather than going off to separate activities.
I recommend you read these CM chapters and then make note of what you take away from them, then use that to make a short list of important characteristics *for your family* for the activities you choose. That will help you decide *what*, *when*, and *how many*.