The reasons for Red Mages not getting Spellcraft:
Reason 1.
Red Mages aren't supposed to be masters of magic. They view magic as a means to an end. It is important to understand how to utilize magic as effectively as possible, not to understand its every nuance and articulation. Red Mages are so diverse in their skills that they lack detailed knowledge in any field. They cannot wear heavy armor. Their proficiency with martial weapons is severely limited. They do not gain the most powerful or unique spells of white and black magic. (Though you can take feats to excel in many of these areas, just as you can take feats to improve your Spellcraft).
Reason 2. Like you said, we gave Red Mages six skill points a level. This was so that they could have a huge variety of skills but never truly excel in any of them (except Charisma-based ones). They can spend some of these points into Spellcraft if they wish. If you look at their class skill list, it's quite an odd smattering. Most of it is very situationally useful skills (The exceptions are Diplomacy and Bluff, buf red mages are the Charisma masters).
Reason 3. We wanted to preserve White and Black mages (mostly black mages) as the masters of the technical magics of the world. Red Mages do not have Knowledge (arcana) either, not until they become Red Wizards to they gain other knowledges.
Point 4. Let's look at what Spellcraft does. I'll go through them in order.
http://www.d20srd.org/srd/skills/spellcraft.htm
1: Glyph of warding: This doesn't really exist in this campaign.
2: Identifying a spell being cast
This one is pretty major. One of the biggest reasons to do this, though, is to counterspell. Red Mages have
Dispel. They don't need to know what you're casting to counter it. Another major reason is to help protect yourself and allies against it. White Mages are much better at protecting their allies than Red Mages. A Red Mage's response to an enemy spell caster is to maim or disable them.
3&4: Learning spells in this game does not require Spellcraft.
5: Detecting what kind of magic an item is putting off is useful, but again, a Red Mage can still tell that it IS magical, and then Identify it. This isn't a super-huge restriction, and goes back to the usefulness of having a White or Black Mage in the party.
6: Same as #1, identifying a magic symbol will be rare.
7: Identifying an active spell is neat. But you know what? You can
Dispel it whether or not you know how it works. Problem solved.
8: While identifying magically altered items or environment is situationally useful, it happens rarely. Moreover, in this campaign, it will not be as common as vanilla D&D. You can tell it's magical, and guess what, if you don't like it? That's right. Dispel.
9: Same as #1. Scrolls do exist, yes, but a Red Mage does not need them. Red Mages can already use almost all of the wands in the game, and the ones that they can't they can have tons of Use Magic Device.
10: Identifying a spell that was cast upon you after a saving throw is nice. I don't have a lot of argument for this one. What might help is that Red Mages have pretty good all-around saves and special resistance to enhancing magic.
11: Identifying potions is not what Red Mages are about.
12: Similar to #1. Dimensional Anchor isn't a player usable spell.
13: Identifying unique magic effects. The save DC is so high for this one that even a mid or high-level Red Mage with Spellcraft as a class skill would have trouble hitting this. This is the realm of the Black Mage.
So there you have it.
tl;dr
Red Mages are not specialists in any one aspect of their class, including Spellcraft. It is to preserve White and Black Mages as the true magical masters. Red Mages already freakin' rock.
This message was last edited by the GM at 13:37, Wed 02 Feb 2011.