Maybe that stuff is true but I think it hurts 9-11 truth to use it.
I dont think there would be a need (or surreptitious manner) in which to replace the perimeter columns! The fuel in the wings and the engines were the most substantial parts of the planes and at that speed tore right through those hollow perimeter columns/wall assemblies, leaving their rough outline on the buildings facade.
If I were you I would just stick to the facts that prove the use of explosives:
There is NOTHING theoretical about these facts:
-The speed and symmetry in the destruction of wtc 1,2&7
-WTC7's implosion
-The Squibs and the Explosiveness of wtc 1&2 which literally erupted creating massive debris fields, pulverizing most of the 160 tons of concrete and blasting it, the superstructures and perimeter wall assemblies and building contents all over the surrounding streets! The streets were strewn with thousands of body parts. And despite a two years search for human remains (at Freshkills Landfill, SI) there remained no discernible genetic trace of 1100 human beings. They remain: 'unaccounted for.'
-The witness and first responder testimony.
-The 99 day fires. With excessive heat *up to 2800f days after 9/11 (see Bechtel and NASA readings even weeks late).
-The elemental iron microspheres
-the Molten metal: See: fema bpat
http://911research.wtc7.net/wtc/evidence/metallurgy/WTC_apndxC.htm
-NIST's refusal to even test for explosives despite the procedural mandate to do so. And what their spokesperson said when asked. 'why not?' 'Its a waste of time to look for something that isn't present" they replied.
-Danish hero Dr Niels Harrit et al's study is undeniable proof of the presence of advance-engineered thermitic explosives in the WTC dust. Like the Anthrax attacks of the same time period, it leads right back to US military labs and contractors.
And the highly revealing clip used in The NORTH TOWER EXPLODING VIDEO
http://www.youtube.com/watch?v=hSApOavkHg8
There's more.. but this should be enough for most reasonable people to realize that, at the very least, a proper investigation (you know, one that actually considers the evidence and does not begin with it's conclusions) is needed.