Every time a new season airs, posts like these are submitted, and for the most part, they miss the point.

For one, when your average person uses the term "plot hole", they're usually referring to bad writing. Most of what you've written here can be dismissed as semantical reframing.

Let's look at one of your points here.

So when Daenerys arrives at Westeros to find an empty Dragonstone, the writers want to achieve a moment of triumph for a much anticipated moment for both character and audience. Would it have been more realistic for there to be a garrison or spies or assassins? Probably yes, but none of them have anything to do with the storytelling. That scene has a place in a wider story, and ruining it for the sake of logic doesn’t really have anything to do with making it a better story.

This may or may not be a plothole, depending on who you ask, but at the very least, it's dumb writing. Jaime establishes earlier in the episode that Daenerys is likely to land on Dragonstone. If this seems to be common knowledge, why not take steps to somehow trap her? Cersei seems like the kind of crazy person who would lace the entire castle with wildfire and have a lone archer or something wait for their arrival to ignite it.

Perhaps Cersei thinks this plan is dumb, or perhaps she thinks sending men to guard Dragonstone is too risky or whatever. The point is, is that Cersei (or Jaime) never even seem to think about this. Even a simple line of dialogue like Jaime saying "I still think we should have sent men to Dragonstone" and Cersei dismissing it with "No, that's foolish" or whatever would indicate to the audience that the characters at least thought about it.

As it stands, the only assumption we can make as the audience is that the characters did not think of this. As far as the audience knows, the characters simply didn't think of guarding or trapping Dragonstone in any way. This is what people mean by "plot hole". Is it necessarily a plot hole? Well that depends on whether it seems realistic within the context of the show's universe. Jaime is a pretty smart guy, are we as the audience suppose to believe he simply didn't think to guard a critical ancient castle where they know the enemy is about to land? If not, then that can be construed as a "plot hole" (given that it directly contradicts Jamie's character). Or maybe it doesn't, characters, even smart ones, make mistakes. Either way, it's dumb writing.

You're other points are also pretty bad.

TV episodes are edited and omit information that the viewer doesn’t need to see. Littlefinger time-travelling and Euron building ships over unspecified periods of time should not really be used as points of criticism

No one is criticizing Littlefinger's time-travelling as a "plot hole", and even if they were, you can understand what they're getting at without arguing semantics. It's not exactly bad writing on the writers end, just really jarring. The simple problem is that the show doesn't illustrate the passage of time effectively. In earlier seasons, when characters would travel somewhere, they would often be off-screen for the majority of the episode, or even a couple episodes. This gives an effective passage of time, it's been quite some time since this character has been on-screen, and the explanation was that he was travelling.

Compare this to Season 6, where characters are in one part of the world, and in the very next scene, they're across the continent. It's jarring because we really don't know how much time has passed. The audience needs "breathing room", so to speak.