I personally believe all of these mods, or the features they have, should be part of the vanilla gameplay one way or another.
The vanilla game is currently too limited, and should be expanded in order to allow for more complex builds even in vanilla games.

Mods are great, but they have one obvious drawback: they're not native and officially supported, and can break at any time. This makes them very unappealing to use for larger projects.

Integration of these mods in the game should also allow the developers to apply their own insight as to the resource requirements and other balancing details to better integrate with the main game.

I don't expect most of these mods to be added to the game as-is, but rather in some form that meshes well with the vanilla gameplay.


Note: Some of these mods may be broken or buggy, but are here for the sake of showing what could be.

My personal comments on mods:
500m/s speedmod: The game has long improved since its originally set the 100m/s limit. Sure, if you fly straight into a flat surface you'll clip either halfway or completely through it, but that's even true at 60m/s. Meanwhile you can actually walk around on ships at 300m/s these days, without teleporting out of your ship suddenly because of synchronisation issues. I think 500m/s strikes a good balance between performance and stability, a balance that 100m/s or 360km/h (that's less than half a jumbojet at cruise speed!) doesn't quite hit.

Aerodynamic physics: I think this could improve vanilla gameplay considerably, by allowing people to build airplanes, and having to compensate for atmospheric compression heat when entering the atmosphere. Its current implementation has issues though, so a vanilla implementation would probably require additional effort.

Animated interactions: The vanilla game severely lacks proper animations that indicate when a player is busy, and also help immersiveness. There are a few mods in this list that add animations, though they're often broken or flaky due to the current state of the animation system.

Additional sounds and LCD textures: The vanilla game severely lacks these! There should be at least some fairly extensive base set of images and sounds that the player can use with their contraptions. The current ones add some aesthetic value at best, but they're far from useful, especially the sounds, which have great potential to be used as automated announcer on one's base.

AI Sound packs: Imagine what scripters could do if there was a proper soundpack to use, or even better, Text To Speech from the Programming block? THEN programming blocks in the game will become truly useful

Camera panning, Damage indicators, Easy inventory, Door label, etc etc etc: These are small tweaks that go a long way making things possible and keeping it fun.

Energy weapons,Tractor beam, EMP/Ion cannon: I think the game should have more types of weapons, and also weapons that only use energy without chewing threw physical resources that need to be farmed, otherwise meteorite storms are impossible to keep up with.

Wind energy/wind mills, Hacking computers, Transporter, etc: The game needs more options, more things, more ways to play the game, more ways to gather resources and energy, more ways to engineer rather than only the obvious simple solutions.

Reduced bloom, etc: I think the vanilla game has some strange things that don't work well. The amount of bloom and flare and glare everywhere is one example, screens with high resolution things on them arent' even readable because of it sometimes.

Therman Mechanics: I think this would add a great deal of engineering to the base game which would in turn make the game a lot more fun. You could shoot eachother's cooling and overheat the other ship, you could go even further and have tracking systems based on thermal footprint, all these kinds of things become available if you add thermal mechanics to the base game.