Well, if you're looking for a slightly more casual experience then
Avorion,
Endless Sky, and
Rebel Galaxy are all good starting points if you want a good open-world space adventure without needing to dive too deep into any mechanics with a manual at your side.
Pirate/Bounty Hunting? Check.
Want to just Trade or do courier work? Check.
Ship Customization? Want to surprise some pirates with a BFG packing freighter? Check.
Fleet Building? You can just putter around by yourself if you don't want the trouble of managing a fleet.
Hostile Alien Invasions? You can leave it to the big boy factions if you don't want to deal with them.