Would you prefer that I do the child tspans on the existing tutorials, or should I just spend a little more time and flowtext it all (and do the bold in that)?
tspans won't be lost, we will have a command "flow text into shape" which will make flowtext out of regular text, preserving all formatting tspans in it (but removing line tspans of course).
Actually I suppose the better question is... If it is done with the tspans in the tutorials current form, will the text still be editable via the Text UI?
Yes. It's editable as usual, and the formatting is not lost in editing. You can try it.
If so it makes sense to me to do that instead of flowtext (at this point), so people can edit the text w/o the XML editor...
Sure, flowtext can wait, formatting tspans are orthogonal to that and won't be wasted even when we move to flowtext.