In fact as BPWT has no immediate intention to go to PB for a looksy............
SLT - trains the stance and the elbow
Wall Bag - trains elbow control, short punching distances, timing, precision
Dahn Chi Sau - Develop the elbow
Chum Kiu - Develops the, kick, step, pivot, the easiest way for fighting, balance, syncronicity (specifically Bong/Wu - Kwan Sau)
Muk Jong - Improves "shock force", precision, timing, elbow, balance, cut the way, limits of actions, syncronicity, chum kiu
Bil Jee - How to cut ones losses
Luk Dim Boon Kwan - Improves force, punching power and precision, improved foot speed, timing.
Baat Cham Do - Awareness of danger, Improved foot speed and evasion tactics. How to fight any other weapon (expect firearms)
Poon Sau - force improvement, lat sau jik chung, punching power.
Seung Ma/Toi Ma - Balance, structure, step, alignment, force
Laap Sau - improve the elbow, syncronicity of punch/jut sau, rotation of bong sau, smooth changes, balance, cut the way
Chi Sau/Gor Sau/Sparring - uses all the above.
There you go. Basic thinking. Now you know everything.