Shalom,    The simple fact is that those topics are all interesting to people and so its not a matter of which topics to teach, but what books to teach.  Shaar haGilgulim is fairly difficult to find in English and so the classes are very in demand.   If you follow along here there are specific books such as Hafetz Haim, Likkutei Moharan, and Tanya as well as other works that are studied weekly.   Its less a matter of what first to teach and more a matter of supporting the community of people that are attending classes. They want all of the classes and topics. Best Wishes