I don't have experience with CR2008, but page breaks are difficult in CR XI since the
BEST you can do is count lines. Complex rules like you have defined
MIGHT be done in a formula, but in all honesty, I wouldn't like to be tasked with it. There are too many variables the CR is poor about reporting on. For instance, if a row has Can Grow, you don't know how many lines it is one...you would need to count characters and if you use a TT font, good luck. You would need know the number of lines printed (or the height of the sections and the count) to have a guess of where you are on the page, then you would need to know how many lines are in the group/subgroup and how many have been printed to be able to know when to tell CR that you would like a page break.
Good luck!