i am new to gas forging as well...but it does seem that gas is the fuel of choice for bladesmiths the world over...not quite as traditional as coal but from what i've heard (when talking about forging blades) gas has a number of advantages that make it optimal...
as far as "adding carbon to make the steel stronger" goes...thats not really true...adding carbon will make the steel *harder* not stronger...which will mean it can hold a better edge...but also mean it is more brittle...bladesmithing (as far as i've been informed) is about striking a balance between flexibility and edge-holding capacity...the more carbon you have in the steel the better an edge it will hold...but the less flexible it will be...as with most things in this world...its a compromise
