I figured out a way to achieve the first part by using the fntabs plugin where they track all the activities within a tab (such as in the demo here: http://demo.ned.ca). If the activities are marked complete, the section is complete as well. However there doesn't seem to be any method yet for obtaining the relative referencing that I mentioned. Or is there?
Thank you for confirming my finding, Derek. What would considerably help us out is if there were a way to mark a section complete (not just an activity) combined with defining access restriction in a relative way (e.g. has completed the previous section instead has completed section A). They way we could easily swap different sections, without having to change each individual access restriction to adjust to the new section order.