Strength of the Forge

Legend of the Five Rings card from Samurai Edition, Rise of the Shogun

Card Type: Spell
Gold Cost: 2
Keywords: Earth
Card Text: This Spell's Gold cost may not be reduced or ignored.
Reaction: When paying a Gold cost, bow this Shugenja: Produce 2 Gold.
Focus Value: 4
Legality: Age of Enlightenment (Lotus), Race for the Throne (Samurai)
Deck: Fate

Printings

Rarity: Rare
Flavor Text: "Your deception is at an end, Kinuye," Bairei said. "Your sickness has no place in the Phoenix."
Artist: Eric Lofgren
Card Number: 152
Publisher: Alderac Entertainment Group

Erratum: Reads, "Strength of the Forge 2G 4FV This Spell’s Gold Cost cannot be reduced or waived. Earth Reaction: When paying a Gold cost, bow this Shugenja: Produce 2 Gold." [MRP, Samurai Edition, 25 July 2007] Comprehensive Rules, Samurai Edition, with specific card rulings, final version, May 2009, p. 158

Q: If Claiming the Throne does not actually have any costs (as per ruling here http://www.alderac.com/forum/viewtopic.php?f=59&t=74318)
Can you use Strength of the Forge to pay 2 gold for it? And if so, does that not imply that Claiming the Throne requires a cost?
A: You may not bow Strength of the Forge to pay 2G for the 10G payment option in Claiming the Throne. Dan Jacobson, "Commanding Favor, Claiming the Throne", 1 Mar 2009
Q: Isawa Chinatsu has a Strength of the Forge attached. I want to play another Spell that has a gold cost of 4. (C)an I use both Chinatsu's and the Spell's Reaction to pay for it?
A: Yes. Zen Faulkes, "Simultaneous gold cost payment", 16 Aug 2007
Q: Chinatsu has two Strength of the Forge attached. Can I use both of them if I can straighten Chinatsu after casting the first one(?)
A: Yes. Zen Faulkes, "Simultaneous gold cost payment", 16 Aug 2007