So apparently no one knew what I'm talking about. Therefore I'm going to attempt the list myself. Please feel free to add on. I assume IM3 will bring to light much more of these.
So, starting with the most basic, Tony creates the:
IM mk I to defeat terrorists who are using his own weapons.
IM mk II to perfect flight after crashing in the desert.
IM mk III after testing the altitude record and discovering an icing problem.
IM mk V when he realizes Iron Monger attacked with little warning and he had to suit up at home before flying there to meet him (expending a lot of power)
IM mk VI after almost dying from the Palladium core and the discovery of a new element
IM mk VII after the battle with the Hammer Drones including multi-target missles and a more rapid deployment feature.
Iron Legion after the battle with the Chitauri
Brute armor after seeing Hulk in action
Destroyer armor after hacking the SHIELD database
the ability to call the armor to him mentally after seeing Thor do it with his hammer.
etc. etc. etc.
My problem with this is that he built all those armors for different reasons than what you posted...the new ones anyway.
I think he doesn't actually develop the ability to use all the armors at once until later in IM3 itself. Tony locked himself in his warehouse and spent all his time building new armors for a year because he was paranoid after the events of the Avengers and I guess didn't really want to go outside and only felt comfortable building his armors and being inside them. That doesn't mean it was directly to combat the Chitauri, and given what I said earlier I doubt he ever considered controlling them all at once.
If the armor descriptions are true then Tony did not build the "Hulkbuster" armor to combat the hulk but merely to handle excessive labor tasks. It's not even meant to be piloted by a person, which is why the anatomy of the suit is weird.
I can buy the Destroyer armor as a contingency plan.
Not sure if he wanted the ability to call the armor to him because he saw Thor do it...it's more that he just feels really uncomfortable without the suit on after seeing what happened in the Avengers because he is more or less powerless without it. He saw all of these incredible things and without his suit he is just an ordinary man. As Cap said, "Take that suit away and what are you?". That line probably stuck with him [blackout](in fact we know it did thanks to spoilers)[/blackout], and he is using Extremis as a way to remedy this. So you could say Extremis is a response to what he experienced in the past, but I think in a different context than what you are implying here.
In general, Tony did probably build a lot of his suits for specific purposes he might need in the future, since he had the time to given he locked himself up for a year and did nothing but build suits, but I don't think he built very many as contingency plans based off of what he fought in the past. The only ones that fit that bill really are maybe the space armor and Destroyer. Otherwise everything else he has built in IM3 is based off of obsessiveness.
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