Well, I don't see anything obvious to criticise about what your interlocutors posted; their statements seem plausible enough to me, and if there is actually a knockout argument against them, I don't know it, because the person who seemed to disagree (you) was busy making childish noises instead of making it!
> jet fuel/steel beams
This debate was carried out sufficiently publicly that I got the sense people actually ran experiments confirming the pro-beam softening/structural failure/whatever case; certainly the "truther" case should have been taken seriously before that, and with decorum always because there is no situation in which any debate in a moderatable forum benefits from playground behaviour.
> jet fuel/steel beams
This debate was carried out sufficiently publicly that I got the sense people actually ran experiments confirming the pro-beam softening/structural failure/whatever case; certainly the "truther" case should have been taken seriously before that, and with decorum always because there is no situation in which any debate in a moderatable forum benefits from playground behaviour.