1) Is this spell restricted to Dwarves? The source of the rules and the access to dwarven weapons implies that it is, but nothing in the spell description in the SRD states "Dwarves Only."
2) Can this spell create a different weapon per casting? For example, can it produce a longsword 1st cast, greatsword 2nd cast, composite longbow 3rd cast?
3) Can the weapons in this spell have other non-magical properies? For example, can "the weapon of my choice" be a +1 flaming cold iron waraxe or a +1 guided silver greataxe?
4) If I create a weapon that is also armor, do I get the benefit of the armor? For example, a spiked heavy shield is listed as a type of weapon. Can I create a spiked heavy shield as a weapon and get the AC bonuses from it?
5) Can I cast Greater Magic Weapon on this weapon?
6) The spell states that if it leaves my hands, it disappears. Does that mean if I sheath the weapon or sling it across my back for any reason (to show non-hostile intent or to pull out spell components) that it disappears? Or does that just apply if the weapon leaves my body (I get disarmed or try to throw the weapon, etc.)
1) GM fiat I guess. SDR often leaves such restrictions away. There are spells, which normally only followers of specific gods know. Thats not mentioned in the SRD.
2) It doesn't say it is he same weapon every time. So yes, it can be another weapon with each casting.
3) Per spell description no. I would allow it instead of the magical special ability. But to do so would be a HR.
4) I guess yes. It is part of the weapon. But it would count as nonmagic shield, as the enhancementbonus is a weapon enhancemenr bonus.
5) I guess yes.
6) In your link it states: "and if removed from your grasp, it vanishes and the spell ends immediately." Sounds like it was meant that it disappears when you're disarmed. But it is unclear. And as such if it gets no FAQ, it is again GM fiat.
3) The Spell doesn't sat You Can make it could iron - i would say no. but if You choose bane (what ever You are fighting) the bonus becomes +3 an overcomes DR A's silver and could iron
4) You would only get the spikes not the Shield/armor so no and se 6)
5) yes it a weapon You Can make it better
6) leaves hand if You for Any reason is Holding the weapon it's gone. You could sheath the weapon and keep You hand ón it - but would You really remember to keep your hand ón the weapon for half and hour?