I won't deny that she did seem to learn pretty quickly, but Luke also learned fairly fast. Maybe not quite as quickly but fast enough to not make it hard to believe for me. I will agree that the film would have been better if she had either some time or training. It's not like Han Solo hasn't been around Jedi enough to have been able to give her some tips, but since Luke was never put in a position where he had to learn to fight that quickly, we don't know how quickly a Jedi can pick up on things.
And that's not a giant mess of coincidence to you?
You missed my point about not explaining the coincidences within the film itself. Coincidence is a mainstay of storywriting. You are allowed to have them in a story because they do also happen in real life and often make up the basis of interesting stories. What is bad storywriting is wild
coincidence. Stories where coincidence upon coincidence happen for no explainable reason stretch your credibility. Even a throwaway line can prevent that.
Let's look at this through the lens of the story as it was presented (i.e. before the Prequels). Two droids escape from a captured ship because a pair of gunnery officers decide not to waste space bullets on their pod. The droids are captured on entirely different parts of the planet by the same group of scavengers, brought to the same place, and sold to their owner's long lost twin brother.
I'll give you the gunnery officer not shooting the pod. However, let's posit that this is the coincidence that results in there actually being a Star Wars. A New Hope is the first film in the franchise, so it's allowed one as a central conceit. What follows though is not wild coincidence. R2D2 was looking for Ben. He would have tried to put the pod down somewhere near where he'd expect Ben to be. It's not a coincidence that Ben would be living near Luke. And the desert of Tattooine is probably like the Australian outback. There probably isn't another settlement within 20 or 30 miles of where Luke lives, hardly surprising that they happen to bump into him.
The group (now plus the person the droids were sent to find, whom they found with little difficulty) heads to town, where they contract the pilot of the only ship in the system capable of outrunning the Imperial ships (we're explicitly informed of the ship's speed with regards to big government ships) who conveniently happens to be between jobs and looking for work at that exact moment.
We have no idea how many other ships there were that could have avoided the blockade. Mos Eisley is supposedly a hive of scum and villainy. It's not the least bit surprising they find a good smuggler there, especially since they found Han specifically because they were looking for someone like him. They didn't just bump into him in the bar and knock his drink over. Ben specifically goes looking for someone. That he turns out to be such a good choice is not a coincidence but part of the story. Interesting things should happen in a story or there is no point in watching it. But it's not a coincidence. The EU probably has a book that mentions the back story every single person in the cantina by now
I'll bet that there were other people in there who would have been suitable.
They don't arrive where they're going until after it's exploded by a giant space laser, after which they're 'captured' and manage to rescue the person who originally sent the droids after the person they're looking for.
Once again, coincidence isn't an issue, it's wild coincidence that is the problem. Leia, Vader and the Death Star all have very good reasons to be there which are explained as part of the plot. It's not like they stumbled upon the Death Star en route to deliver the droids. Given how big the empire is supposed to be, that would be a wild coincidence.
They escape (albeit that one isn't luck, thanks Vader) and return to the rebel base, where Luke is one of their best pilots, vouched for by his childhood friend who just happens to be there too and is also a pilot. Luke ends up being the only one who can destroy the giant space laser with his magic telekinetic powers that he discovered literally three hours ago.
Okay, I'll give you Wedge as a wild coincidence. So that's one. And it's not exactly one that drives the plot anywhere really. Nor is it completely beyond belief that someone who grew up with Luke would end up in the same place. Had Luke's uncle and aunt allowed him to go, he probably still would have ended up seeking out the rebels with Wedge. But fair point, I'll give you Wedge.
I'm not going to give you Luke being a great pilot, we've established that he is by that point. We've also established that Luke could hit a target that size and has been doing so for years. The telekinetic powers aren't something new so much as something he is told to use again rather than the new technology he has been given.
The hero being in the right place at the right time is something that is the central point of almost every action film. The hero being the only person who could do something is a major part of many fantasy and sci-fi films too. But we don't watch films about the also-rans. We watch films about the hero.
And that's not a giant mess of coincidence to you?
As I've pointed out, the only wild coincidence is Wedge. And that's not a big one. There are other coincidences but they are explained in the film. Now compare The Force Awakens. How many wild coincidences are we asked to swallow? And what really galls is how many could have been explained away.
For instance, we can explain Han Solo turning up pretty easily. There's no reason Poe and Han can't be acquainted, so there's no reason Poe wouldn't know that Han is looking for the Falcon. If Poe spotted the Falcon earlier while on his secret mission, he might have sent word to Han. A couple of lines from Han about how he'd heard the Falcon was in the area and maybe a nice bit of banter between the two once at the rebel base could have cleared that up. And that's just off the top of my head. What upsets me is that the scriptwriters are lazy enough to stretch credulity beyond belief without even the slightest attempt to explain the coincidences.