So, maybe it is an issue of us describing two sides of the same coin? (Ok, it seems like Mok deleted his post, so this might not make sense)
Like Pavel mentioned, and how I mentioned earlier, the seeds are exactly like the basic tools you'd hear if you asked a boxer about their repertoire (jab, cross, hook, etc) and stuff like that.
Of course energy is going to be an issue, because body mechanics are a huge component of what makes a style a style. The engine won't run without the fuel, but you still need an engine first.
So, with that being said, everything O has mentioned is basic (and IMO compulsory) from a "gung fu" POV, but, the seeds are at an even more basic level (kuen jung). IMO, seeds are style specific to a certain degree, mainly from the angle of what the art chooses to particularly focus on. The two combined will give you a stylistic expression.
However, if you take a seed, lets say something like yat ji choi, and you shoot it through the five elements, you can have several different variations, all manifesting different types of ging and energy. So, there needs to be differentiation between body mechanics that are foundational, and body mechanics that come from more advanced usage and methods of play.
Ping choi can have similar issues as well, oscillating between fire-based gings, wood-based gings, and other variations based on qualities of penetration (chyun, dim, etc). But the basic ping must come first.
You can take gold splitting fist and emphasize different energies with it. You can emphasize more jong ging (colliding) or you can emphasize lok (dropping or falling), or rolling. If you get caught out, you might have to switch to wood to emphasize squeezing and bik. However these plays are all meaningless if you do not understand the basic seed of gwa choi.
Take a boxer for instance. If they learn how to jab, do they learn to jab first, with a decent amount of body mechanics (which would be analogous to the training we have with our stance, structure, etc) and then go from there? Or do they learn all the various energies involved and types of jabs? From my experience, they start out with a basic jab that has body mechanics and as their game develops, they pick up other variations that suit different strategies and situational factors.
Peace
