Hey Ford,
Regarding all the different styles looking the same, they had to, and still do look the same...but looking the same doesnt mean being the same, particulaily with Xingyi or any other "movement based" (principles) MA.
When you apply a move in a fight, a move you train in a certain form for example, the move isnt and most of the times shouldnt look exactly the same. Training it teaches angles, point of contacts, stepping, power generation, etc, things that arent exactly obvious and you can manifest and mix them in infinite ways, not just "exactly the move you would do if your doing a form".
But you have a point, some things are purely there for....i dont know what for. Should most certainly be discarded.