And that's the whole point. He - or anyone - isn't control of anything.
Yet his endgame is to manipulate two specific people to be at a very specific and remote part of the world at a very specific time through a series of his actions.
No it isn't. Yes, he's happy that he gets to do all this in person because that's gratifying and dramatic. He never needed it to happen in person in that specific place and time, though. As I already said, if no one shows up he can just release the video to the news and cause the exact same rift. He'll be disappointed about not getting his face to face revenge, but his plan would still have worked.
To put it into perspective, only look at the very last link in the chain: Tony finds the body in the hotel room and puts two and two together quickly (which in and of itself takes Tony's ability of deduction on a lot of faith) enough to fly off to their dinner date on time.
But a million infinite number of butterfly effects could have happened in between, anything from Tony having a slight pang of ennui and ultimately deciding to go home and give Pepper a hug, to the concierge calling in sick that day so the cleaning person unknowingly walks into the room. Or here's one: Rhodey probably should have died which would have changed Tony's psyche completely - let alone his ability to give a crap.
A) Tony didn't find the body, he was alerted by Friday who monitors news reports all the time.
B) Zemo deliberately called people into his hotel room, which guaranteed that someone would find the body since it's just sitting in the open bathtub.
C) Rhodey actually dying (which honestly could have been an improvement to the film) would only cause an even bigger rift between Stark and Cap and make Stark even angrier about the fact that his best friend died because Steve wanted to protect a mindless assassin who was also guilty of killing Tony's parents.
I'm pretty forgiving when it comes to contrivance being a necessary evil in popular fiction, but there comes a point where it completely breaks immersion for me. Which is unfortunate because it completely spoils what would have otherwise been a fun romp.
Here's the thing though, it could be argued that had T'Challa not been there, that Steve and Bucky might have gotten away. Most of that entire chase sequence is Steve staving off T'Challa, not the Interpol (or whoever they were) guys. BP's interference cut off any alternative escape route available to them. More importantly, it gave Steve someone of equal skill to combat. They may not have escaped, but I like to think the odds of Steve and Bucky against all of Deutschland's finest are pretty good. They may not have been able to elude capture forever, but they might have held out long enough or gotten far enough out of the city (or country) to have them sent to a different detention center with a different doctor.
OR
T'Challa was always part of the plan. The bomb's yield and position and time of detonation were specifically chosen to target the podium and kill T'Chaka. Then we're right back into Zemo is a prophet territory. I mean what if the King had some bad room service the night before and had to make an emergency pit-stop and the start of the conference was delayed 15 minutes.
**And just to clarify, I don't "hate" the film by any means. Hell, I've seen it five or six times. I just think, for being the pivot point of the entire franchise, it could have used a much tighter script and plotting.
And when I say "worst," I do so on the grounds that I have to often remind myself of Thor 2's existence. And I also like IM3 a lot more than most see to - I think Pierce's performance is brilliant.
The film is abundantly clear on the fact that no one knows Black Panther exists. Theorizing about how Zemo planned for the Black Panther as 'proof' that he knows too much is absurd. The bomb targeted the podium because it's the center of attention and the obvious target for anyone trying to disrupt the event (which is what the expected motivation of the bomber was supposed to be). The fact that it was King T'Chaka standing there is pure bad luck for the Wakandans.
As for Steve and Bucky escaping - could they? Maybe so. But the movie offers absolutely no reason to believe they *would*. Steve didn't go there to prevent Bucky from being captured. He went there to make sure Bucky didn't get killed or kill any cops. The only reason it turned into a running firefight is because Black Panther showed up out of nowhere trying to kill Bucky. Without BP, if Bucky tried to run, Steve would be fighting him - or they would hole up in an empty building somewhere and argue about it until Steve convinced him not to run.
Also, the running chase scene happened in Romania and the UN dispatched the Doctor Zemo impersonated from Geneva, so just crossing border lines wouldn't seem likely to change that aspect of Zemo's plan, anyway. The movie is also entirely unclear on whether Zemo actually needed advance notice of who exactly he was going to intercept in order to complete his forged documents on time, or whether he already had most of what he needed lined up and would only need to quickly fill in the blanks from his victims id and hit print. (Real world, yes, he'd need time, but the MCU has far more advanced espionage technology than the real world.) Ergo it may not matter in the slightest who exactly the UN chose to send. Worst case scenario would be that Barnes is arrested so far away from Zemo that Zemo can't get in position in time, which means that plan's out the window. But nobody's plans always work, so the idea that there was a chance his plan could fail is hardly some incredible disqualifying insight.
And even then, there's a real possibility that his skills and knowledge of the system would be enough to finagle an interview with Barnes anyway, even if he wasn't able to impersonate the first doctor called to the scene.
