we know that the speed they're using when not in hyperspace is a sublight speed.
I agree with what you said except for this. Yet, I'm
close to agreeing with this. I might agree with it if you phrased it
"we know that one of the speeds they're using when not in hyper-spece is a sublight speed."
Even that doesn't cover it. When we start talking like this, it sounds like we are talking Trek Tech.
Star Wars is a fantasy. It's as much a fantasy as the kinds of stories we played out using 20 sided dice and tossing saving throws.
In
this fantasy,
ships go between stars, just like a car goes between towns. Simple as that. The point of the story is not to get mired in the technical details of how this happens. By the time someone examines whether the method of transportation between systems is consistent from one scene to the next, everything starts to break down.
Star Wars is an illusion. For the first film, they actually built huge sets, and great vistas, to
sell us on the idea that this completely unreal place would
feel real. The light speed thing is just another way to do it. Like the set for the
Millennium Falcon (which can't actually fly) it adds to the illusion while never adding up.
I'm not saying this to attack what you said. Not at all. I think it's actually so close to being accurate, and yet, in reading it, I realized that it misses the point of
Star Wars, that it's a romantic fantasy ("romantic" in the sense that's it's classical storytelling with big characters and sweeping emotions). So, while I agree with you, once I read "explanations" like that, my heart sinks.