...I look forward to input on what people here think are the strongest arguments against both Gage and truth movement...
The problem is that the strongest arguments are not the most persuasive arguments in the context where we meet truther claims. And that for a few big reasons:
By the strongest arguments I mean those arguments which are logically and evidentiary the most rigorous. Taking the claims for CD at the WTC as the working example. The base observable (and undeniable - I won't consider the fringe lunacies for this post

) facts are that on 9/11 an aircraft flew into each tower, did some damage, started fires, fires were not fought and after a period the towers collapsed. Prima facie those events caused the collapse - it was a result of the impact and fire damage. There have been multiple technical analyses made which give coherent overall explanations as to why the collapses occurred from that sequence of events. Any minor faults in or differences between those explanations does not change the fact that there is a far stronger than prima facie case for "impact and fires caused collapse."
The opposing claims from the truth movement allege CD in some form. BUT:
a) All those claims (AFAIK) take the form of "Here is a single bit of anomaly; I say that means CD; you prove it wasn't." So no coherent hypothesis i.e. no case to answer, a reversed burden of proof AND a demand to prove a negative. If we are thinking about
strongest legitimate arguments there is nothing to rebut.
b) The truther claims (again AFAIK) have NEVER been framed as a legitimate coherent overall hypothesis. In the legal sense there has never been a "prima facie case" - a claim which meets the threshold test of "a case to answer". We shouldn't even be responding to them - in a legal setting the defence would not even get called on to present defence because the claim does not meet prima facie.
So that example identifies the"strongest argument" but, as I said, it is obviously not the most persuasive. We are not dealing with reasoning people who are amenable to logical evidence based argument.
In reality the only reason that technical discussions such as those in this forum take place is because the debunkers find them interesting and it can be fun rebutting the technical nonsense. Some of the claims are technically interesting and challenging in themselves and we tend to forget that they are not legitimate "prove a claim right or wrong" argument about 9/11 - specifically CD as the example I chose. They cannot be "prove a claim wrong" because there is no legitimate claim. Merely one or more anomalies that the claimant cannot or pretends cannot explain AND a falsely structured argument based almost always on reversed burden of proof.
Take as an example ALL of the ThermXte and dust threads which have technical interest. Their legitimacy in 9/11 CT discussion is the tenuous link that ThermXte could have been used in CD.
But there was no CD. There has never been a prima facie case for CD. No case to answer.
Now the way I have put all that will no doubt raise some issues. Let's leave the "yes butting" aside for now.
Remember the question was "what are the strongest arguments". The fact that there is no legitimate claim, no case to answer is the strongest argument against CD at WTC. If we are after the strongest argument for objective discussion in some formal investigative process.
But that is not the scenario that RPress's question implies. He asks what are the strongest arguments but I think he needs the most persuasive arguments to put to truthers. And the big barriers there are:
1) Most truthers are not interested in legitimate strong arguments; AND
2) Most truthers appear to be incapable of or unwilling to process legitimate arguments; AND
3) (My hypothesis - which few recognise or want to discuss

) many people become truthers because they cannot process, formulate or present reasoned arguments.
So chasing "strong arguments" in the sense of reasoned arguments is unlikely to be persuasive. The persuasion will most likely have to come from other processes than reasoned argument about technical issues.
And a final "throw-away comment" which could also open up a different complex area of discussion.
... Also I want to address Hoffman who said video of the inward bowing would settle whether the bowing really was taking place or if it was an optical illusion, well there is video of it!
1) Yes there was "inward bowing"
2) NIST claimed that inward bowing started the collapse initiation stage;
3) Other researchers - see The911Forum - have made persuasive claims that the bowing was led by core failure.
4) So we have an argument between the "perimeter led NISToPhyle side" and the "core led NISToPhobes". So what? Why does it matter?
Nobody so far prepared to answer that last point. (yeah -- AFAIK again

)
Reality is that through the cascading failure of the "initiation stage" both core and perimeter failed. And which ever bit went first it makes no difference - the top of tower fell. And in a cascade 'going first' does not invariably mean causal....etc etc....Both 'sides' shy away from the complexities.
The strongest arguments are often too complex for either side.... and that is another bit of red rag to have fun with.
