What advice do you think is necessary to running a "ships in space" game? This isn't a facetious question. To me, unlike Horror adventures which are very unlike traditional DnD, Spelljammer adventures are classical DnD. Explore the Unknown, delve into ruins, and fight monsters. I don't think they needed to explain how to run these adventures, because they are just classic adventures set in a different setting.
I think just the opposite- the setting (space) matters and isn't really explored as a setting in the SJ set. Horror is very much a traditional D&D element and trope. Heck, early D&D was basically survival horror. That said:
Here are some things that make D&D in space different from traditional D&D.
Here are some ideas for making space-based settings and sites, how to set them apart, and some examples of them- asteroids, comets, planets, water worlds, ice worlds, planetary systems, etc. (Which, to be fair, the adventure sticks about one digit into, but it's such a shallow dip into it that I don't think it does the job very well at all.)
Here are some ideas for how space might affect cultures, monsters, etc. (Which the bestiary also sticks the tip of a finger in, but that's about it.) Here is how space elves differ from ground elves because space.
Here are some cool space hazards, such as ion storm, phlogistonic clouds, etc, and ideas for creating your own.
Here's how spaceship combat works differently than waterborne ship combat, especially accounting for the fact that it is in three dimensions.
Here are at least a cursory look at enough star systems/crystal spheres that you can see how much variety they might hold, at least enough to provoke ideas.
That's just off the top of my head. Again, if you find SJ5e satisfying, awesome! I find it to be
disappointing but better than nothing. I think if there was much chance of seeing more material expanding it, it could improve markedly, but since I don't buy much 3rd party stuff these days, I'll probably miss it, and would prefer my settings to have more, well,
setting, in them.