Looks interesting,
I'm looking at space survival games right now. Considering space engineers, empyrion, and elite dangerous right now.
How's the combat and danger in the vanilla version of space engineers?
This game might be worth getting if there are any decent mods for it.
I found an article here that describes some of the mods, and I think the mod where you can be a space pirate seems like fun.
https://www.thegamer.com/best-space-engineers-mods/
Space Engineers is quite good nowadays, provided you enjoy building things, but the combat and challenge is non-existent, even after years of development. There's nothing there as far as I can tell and even mods struggle to provide anything substantial.
I'm not sure if the military DLC made it any better, but PVP is probably okay if that's your thing. SE just comes down to bolting a bunch of guns to a brick and that is the extent of the depth this game provides. From The Depths is a far better choice for combat and gameplay loop, but lacks the polish and easy building system of SE (while obviously not much of a space game either).
Empyrion is also good, but it's quite low budget, and is particularly hard to get into initially. It probably has better combat than Space Engineers out of the box, at least once you progress beyond personal combat (which is nasty). It's not really inferior to SE in any respect honestly (except polish/UI) and features a much larger universe. I can't say any more about it, because I haven't been able to get back into the game for quite some time.
Avorion might be a better choice, at least for consistent combat challenge and combat design. It's theoretically simplistic, but you're always putting time into your ships to make them more powerful and efficient and it just doesn't get bogged down with pointless systems that have no effect in combat anyway.
Elite Dangerous is your go to if you want a game with flight mechanics and mastery of combat. It has actual good combat where systems matter, although these are really space planes and feel nothing at all like space combat. The combat scenarios in this game are however, hilariously limited for some reason, so it can feel repetitive after 60 or so hours if you're not good at diversifying what you do in the game.
Pick up which ever because you can't really go wrong with any at the end of the day, provided you understand SE/Empyrion are games where you spend the majority your time building and mining. SE in particular is build focused, but as you said there's a few cool mods to pad out combat but these don't strike at fundamental problems with combat. I wouldn't go into SE expecting great combat, but maybe salvaging aspects after combat appeal to you (or the explosions), that and the high level of polish SE has (at least compared to Empyrion).