Jake, just as a side note, Sun Lu Tang also learned baji in his youth. Its in Tim Cartmell's translation of his Xing Yi.
Baji also also has a strong affinity with Chen's pao chui or cannonfist.
The training methods seem to overlap, in my experience, among baji, xing yi and Chen's taiiji's pao chui.
However they all have their unique way of delivering power---baji seems to also have a lot of elbow work and kao which tends to blend well with the other two.
As far as bagua goes, it not only marches to the beat of a different drummer, it has its own orchestra and musical scale.
"Its better to build bridges rather than dig holes but occasionally you have to dig a few holes to build the foundation of a strong bridge."
"Traditional Northern Chinese Martial Arts are all Sons of the Same Mother," Liu Yun Qiao