The craft skill if just what you use for rolls.
Going by examples of magical items, yes, you are restricted to what the Craft skill can make. It thus seems that Master Craftsman is in no way equal to having spellcaster levels.
The best road to go seems to be Armorsmith, as there are actually many WOndrous items that are technically also armor, and you should be able to adapt the skill freely (leather armor, leather coats and cloaks, bags, bracers, helms, torcs instead of necklaces, gauntlets and gloves, greaves and sollerets instead of boots and shoes, girdles instead of belts...) and all this in addition to making normal armor.
But yeah, weapon and bow making is pretty restricted. It's noteworthy that bows with Str mods have the highest, hardest crafting DC's in the game!
==Aelryinth
Hmmm, I was under the assumption that it replaced spellcraft. I take back my previous statement and instead encourage you to take spellcraft as a skill.
Spellcraft would only work if you had the caster levels to back them :(.
==Aelryinth
Craft(engraver/jeweler)?
Spellcraft would only work if you had the caster levels to back them :(.
==Aelryinth
How so?
Choose one Craft or Profession skill in which you possess at least 5 ranks. You receive a +2 bonus on your chosen Craft or Profession skill. Ranks in your chosen skill count as your caster level for the purposes of qualifying for the Craft Magic Arms and Armor and Craft Wondrous Item feats. You can create magic items using these feats, substituting your ranks in the chosen skill for your total caster level. You must use the chosen skill for the check to create the item. The DC to create the item still increases for any necessary spell requirements (see the magic item creation rules in Magic Items). You cannot use this feat to create any spell-trigger or spell-activation item.
I believe this reinforces my first thought... I think it is saying you replace whatever roll you would make, and use your chosen craft instead. But I have already gone back on my decision twice, so... yeah...