I'll touch on a different subject here: Tony and the kid.
I am surprised people dismissing it as a "comic relief" or "teen sidekick" or "audience surrogate"
I loved that part, because in my mind it was more psychological then the rest of the movie combined.
See, Tony IS the kid. When Tony meets the child (by now you probably noticed, that I did not remember his name), they do not develop a usual "competent adult / helpless child" dynamic. They communicate as equals. They trade stuff, they share secrets, they play jokes on each other.
This is the part where two boys interact, just one of them is 40+ years old and is filthy rich.
And that's great, because it touches on the psychology of Tony's reflection. He experiences another bout of growing up. "Aren't you a mechanic? Can't you just ... make something? - Okay."
If you look into this period, Tony never teaches the kid anything (contrary to the usual "adult / child" trope in the movies) but he learns.
And that's essential, basically all 3 Iron Man movies are about Tony growing up.
Iron man 1 is just pure "exit the sandbox and enter the grown-ups world" movie. Tony learns that pain, suffering and death exist in the world. Safety blanket is off and the big boy pants are on.
Iron man 2 has the subplot of Tony accepting his father, resolving his daddy issues. The subplot reveals to Tony, that whatever perceived slights your parents conducted against you (in his case - neglect from his father) - you have to let it go and embrace the biggest gift parents can give: adamant trust in you growing up better and greater then they have been.
And Iron man 3 puts a cap on this, by teaching Tony not to be defined by his immediate successes or singular deeds (because, taken individually they can paint him as either a saint or a devil). Tony learns to define himself by his strengths and weaknesses.
What you can and what you can't defines you.
"A suit was just a shell. A cocoon" Things inside of the cocoon made the suit possible - not the other way around.
Iron man 3 ends with Tony growing up to be a man. With all of his mannerism, he still did grow up - and suit or not, he is a force for good in this world, not an oblivious child as in the beginning of IM1, not a emotional loose cannon as in the beginning of IM2, not a self-centered and self-absorbed maverick as in the beginning of Avengers.
He has his vices and has his virtues, but he is a force for good and a grown man.