Nothing in that first clip says that you can't travel to your own past. And the second clip explicitly says that the new branch reality would suck not because it's missing a stone but because the Time stone is an all important weapon against the forces of darkness. There is absolutely nothing there to indicate that removing the soul stone or the power stone or any other stone would result in a terrible timeline.
'Time travel doesn't work like in the movies' is not an explicit refutation of every possible time travel conception. Avengers isn't even the first movie which used this alternate universe time travel concept, so it literally cannot invalidate all previous time travel movies. And the hypothetical rules I'm talking about are not 'the usual fictional rules of time travel', the fixed timeline concept is actually quite rare in hollywood and there is not a single fixed timeline time travel movie name dropped in Avengers as being a bad depiction of time travel. The movie does not refute this notion at all.
I literally already said that.
No, it wouldn't. And you have absolutely no clue what he might've been doing with his life.
It is physically possible, it is a happy ending, and he did not have to do nothing but hang in the background. There's a whole world beyond just the tiny fraction of things we've seen in these movies. There is no characterization problem, it's great storytelling and the science presented in the movie does not contradict it anymore than the script also contradicts the alternate universe theory.
The Ancient One said "the infinity stones create what you perceive to be the flow of time" at the mark I told you to start watching from. Stones, plural. Less stones mean the flow of time is wonky like losing wheels off your car on the highway.
"Think about it, if you travel to the past, that past becomes your future, and your former present becomes the past, which can't now be changed by your new future"
When Hulk says future, he means timeline. A new future is a divergent timeline, because the old future is still there, there are two futures. One diverged from the other at a point in the past. One future new that you can fuck around in, and one clean, that will hold your original past, so that you can return to the present you left from. It's fucking awkwardly written by a moron, but it's the only way that you can't change the present by changing the past.
It's not really time travel. They're just creating parallel worlds.