ydirbut>
That depends upon the campaign and the characters. D20 is suited to more than just dungeon crawls and treasure hunting, so the skills which would be more or less potent depend upon the situation.
Like I said, the original idea is definitely worth developing more, but as it stands it only uses different rules to create the same effect of the skill system D20 already has. If you're dividing skill groups more or less by party role or vocation, why use them instead of D20 class skills and cross-class skills? As it stands now, the system you propose is more customizable than the current D20 skill system, but only slightly so. By the time players choose their classes, they pretty much know what sorts of skills they want to have, so grouping skills by party roles only adds another step to character creation. Players who want their characters' skills to more accurately reflect their backgrounds since they pretty much have to shoot themselves in the foot to get the character they want. Let's say you have a character who is equal parts priest and con artist (not very far-fetched). The essential skills I believe this character would have are:
* Bluff: for obvious reasons
* Diplomacy: getting into people's good graces
* Gather Information: for finding potential target areas and people
* Knowledge (religion): being versed in my organization's traditions and beliefs, as well as to have another angle with which to influence my targets
* Sense Motive: knowing who can, can't, and shouldn't be conned
* Sleight of Hand: some deceptions that involve the hand moving quicker than the eye
* Could make a case for: Appraise, Disguise, Forgery, Knowledge (history, nobility/royalty), and Perform (acting)
To get the essential skills, I need no less than 3 of the skill groups you list (5 if I also want Knowledge (history) and Perform (acting)), which is not easy to get unless my character has bard, ranger, or rogue levels. A monk or druid (which can fill this role) needs Intelligence 14 to be able to get the essentials. This isn't bad. Con artists are generally a bit sharper than most people would expect. To get all 5 groups that would completely cover this concept, monks and druids would need Intelligence 16 or higher, depending on if you round up or down. A cleric or paladin needs Intelligence 18 to even get the essentials. Not to mention, there is the fact that there is a lot of baggage with each skill group that doesn't fit in with the concept so that, even if I choose not to pick up the various skill groups, I'm having to pay double the skill points for half the ranks in skills that are central to my concept.
lassifying skills by how they function independently of party roles makes creating such a character a great deal simpler. All I need is to pick criminal skills and social skills, and my character would for the most part be complete. Low-skill classes would only Intelligence 14 to get the two skill groups essential to the concept. Not to mention, it more intuitively answers the question of why some skill groups have some skills (Intimidate for the self-sufficient group?) and some don't (statesman would not have Bluff, Intimidate, or Sense Motive?). Dividing skill groups into more general academic, athletic, social, etc. makes it easier to determine which skills go where and to apply them to character concepts.
With the groups set up as you have them now, you pretty much have to explain yourself more than you have to explain the system. If you'd prefer to do that, that's fine, but if you'd rather not, I'm simply suggesting an alternative way of doing things.