Like it had been mentioned, I'd have enjoyed that the beginning had been skipped where we didn't know who he was until Tony Stark connected the dots and have a flash back while everything before was 100% focused on Ben Kingsley being the Mandarin, however unfortunately movies especially blockbusters hoping to have mass appeal have to dumb it down and can't get too clever with how a plot twist is going to happen. People need to be able to see it coming, know what the ignorant hate? Feeling dumb.
Maybe it's because I don't have a personal attachment to the Mandarin like I do Magneto, or Loki or other villains but I enjoyed the idea that the Mandarin was only a ploy to cover up what was actually happening. If there was an explosion in random town, he was used to take credit for it it was to show that no one was safe, even in Bumfuck, Tennessee. From what I saw in the movie, even with those who took the pills to regain limbs and other forms of regeneration they still had to keep taking the pills- So you basically have a bunch of addicts killing for them to keep living- people do that every day more or less. I don't know what would happen if they stopped, that could have been shown with one person 2nd guessing their purpose and not given any more of the pills or if they themselves would refuse to take it and walk away knowing they were going to die anyway.
There should have been a Never Ending Story moment where the kid was being bullied only for Falcor, I mean IronMan to show up and deliver their comeuppance and scare them straight.
Tony Stark's arrogance is why he kept using a not yet ready for primetime player Mock 42 for his suit the entire time granted the only thing it really seemed to have trouble with was the whole going on to Tony with just a flick of the rest like all the other suits were. When the helicopters showed up at his house to level it, let's say he used all those suits to take them out after being caught off guard- he would have lost his ace in the hole just to take out what ever goons showed up where again arrogance he kept that trick under wraps and figured he and pepper could survive without them until he knew when He'd be fighting the Mandarin. You don't blow your load over some goons, you save that shit until you get to the end boss- does no one else play video games?!