To take the sailor example;
Use rope does not mean you know how to rig a boat.
Diplomacy does not mean you know the difference between port and starboard, or the meaning behind other nautical terms and phrases. It's to do with getting what you want from someone without offending them.
Balance does not mean you're accustomed to sea travel (have sea legs).
Knowledge (geography) does not mention travel at sea, or navigation by stars.
And so on.
Why would you use Diplomacy for that when it is covered by one of the Knowledge sub-skills.
The problem isn't that Balance doesn't cover sea legs (Er, looking at the Balance skill again, if it doesn't cover sea legs, what the hell does it cover then?)
It's the fact that you can apply Profession (Sailor) to the other SUB-skills and basically "cheat" the system.
As an aside, it should be pointed out that MOST sailors actually couldn't navigate either. Most deckhands had rudimentary reading skills.
Furthermore, the SRD defines "directions" under survival (Knowledge -geography provides a synergy bonus) as the Survival skill is the skill you roll against to both determine Weather conditions for the next 24 hours AND directions...
In fact, so I was wrong...
Profession (sailor) not only makes Use Rope, Balance, Climb less valuable skills but also Survival and Knowledge (Nature)....
re: Profession (waiter)
Um, you're actually spending skill points in this? Never mind that the scenario you listed is covered by either Disguise and/or Perform (Acting), and/or Knowledge (Nobility and Royalty).
The 3E system has such fine granularity that a BROAD skill like Profession sticks out horribly.
As an aside, would anyone allow this in the game, Profession (Circus/Carnival Performer or Court Jester). Circus performers are one of the oldest professions in medieval life and also one that I think is actually more common to appear as background fluff in modules than say Sailors.
Even before we had many other professions, theee were travelling carnivals so does this mean that I get to "cheat" out by not spending points on the skills like Tumble and Balance?