...To be more exact, there were real exchanges of fire at Tonkin, although mostly against imaginary rather than real opponents (the USN was piss-poor at radar fire control in littoral conditions at the time, seeing "ghosts" everywhere), and there was lots of confusion and apparently a bona fide conviction by many of those involved that they had been attacked. The higher-ups just bloated up the minor incidents, and played down the aspects of US aggression there, rather than fabricating anything out of whole cloth. (Quite probably a whole-cloth story would have been created if all that confused shooting had not happened, though.)
But that's a minor distinction. And surely Star Trek could have "told this story", or any one of the others, even when substituting Trek details - such as a big, heavily armed combat and exploration ship rather than a small, unarmed spyship in case the
Pueblo story was told. That's what artistic license is all about.
1: Kirk suddenly becomes a Romulan. Is it that easy???
I don't see why not. He's not just in a convincing disguise, infiltrating a hierarchial organization where superiors are expected to be obeyed rather than questioned. He's also on a carefully planned mission, and no doubt has extensive resources to draw from. All the secret codes and ship layouts and obscure Romulan customs accumulated by agents in the preceding decades would be made available to him. Or at least as far as "need to know" went - and in this crucial mission, it would go pretty far.
2: Kirk steals this doohickey called a cloaking device. That easy, huh? Just unplug the big alien light bulb and beam me up Scotty!
I have little problem with this part. Since Starfleet knew about the new device, it's not impossible that they had some idea of what it would look like, where it would go, and how grabbable it would be. It's the next concept, that whatever Kirk stole could actually be made to
work, let alone on short notice, that borders on the impossible. Far more probably, Kirk could have stolen a single crucial component that would tell Starfleet what made the new cloaks tick, but wouldn't act as a cloak on its own right.
However, we may have misunderstood the true scope of the operation. Starfleet may well have known a
lot about that device, including direct inside information from a Romulan who was actually working on them. Kirk would then be briefed not only on what to grab, but actually on which screws to twist and by how many degrees so that the thing would come loose. Sort of like some of the Enigma machine captures in WWII: the British sailors raiding the German sub would know exactly what kind of a device to look for, and what accessories and books to take along with it, and also how to prevent Germany from learning that anything was taken.
4: The Enterprise escapes at Warp 9. Since when is it that easy to run away from three Romulans ships, and that fast, no less?
I wouldn't think there's any problem in breaking free from a "siege" by three enemies in 3D space as such. And a warp 9 dash "thataway" would leave the enemy no reaction time, although there would be the very real risk of them giving pursuit. The implausible part would be in powering up for that warp 9 dash without the Romulans noticing and opening fire. Surely the enemy would be aware of the risk of such an escape, and would require Scotty to shut down something crucial that takes a long time to bring up to working order again?
But Starfleet might have been prepared for that very thing, too. Even though Scotty seemingly wasn't in on the plan, his ship might have been rigged to allow for "silent power-up". Indeed, since Scotty had his hands full with the cloak, one of his underlings might have been the co-conspirator in charge of the engines, holding the secret of the quick getaway.
Timo Saloniemi