The distinction between real and imaginary isn't obvious to a child. For a child Santa is "real" for a while, then they realise it's a fictional character, just a figment of their imagination. For some people the belief in God lasts longer, but I still can't see a fundamental difference between a child's belief in Santa and a child's belief in God.
I already discussed that earlier. The difference is in how the relationship is understood. That difference is why some theists rightly get upset when people compare their gods to entities they have no significant relationship with. It's like comparing to someone's spouse as a stranger or acquaintance.
TI'm not sure what you mean by "otherworlds" here. Do you mean something which only exists in the imagination, or do you mean actual otherworlds, like different realms or something? First you say that the distinction between the real world and otherworlds is "damned obvious", then you imply that there is really no difference, so I am struggling to understand what you really mean.
See here. But also, see below.
Star Wars is science-fiction, the operative word being "fiction". Are you saying there is no difference between fact and fiction?
No. I'm saying they're both parts of reality. Though ultimately, we can't say if there's an true difference between the two, aside from one being in a different time/space than humans. From our limited perspective as humans, we usually perceive a strong difference, but for all we know, all these otherworlds do literally exist in parallel universes/dimensions. It's kinda like how if you've never actually been to the Great Wall of China, it might as well exist in the otherworlds to you until you visit the physical location. But unlike the Great Wall, humans, can't ever experience most (or arguably all) otherworlds in that literal way. I also find it good to bear in mind that human limitations necessarily mean our ways of classifying things as being on one side of the veil versus the other are necessarily idiosyncratic. I always ask "in what way can I experience X" rather than "is X real," then aim to respect the answers to that from others as well, given different folks put the veil down in different spots.