One of the things I think Starmade is suffering from is the complete focus upon ship-only gameplay. Build, fly, salvage, repair - all without ever leaving a ship core. Most players like this, but I think it is because there is no alternative (yet). I believe that the game will have more appeal and a wider fan base by looking into astronaut-centered play.
I like the idea of a build-block specifically for items and equipment (I forget who suggested it, and can't find the original post). It would require that the character model be redone so that equipment can be 'docked' to the hand/leg/chest/head.
I think that building armor, guns, and weapons will need to implement some limits to discourage doom-cube and clipping animations. We don't want to build a giant sword that clips through the wielder's head as they run, or boots that clip through thighs. When designing an item/armor, a 'build helper' mechanic can limit where blocks can be placed to keep them out of areas that would clip through the astronaut. This means that all items will have to have a maximum and minimum size, and a rough shape depending on function.
I'm not sure which idea I like better - equipment that breaks away in voxels as each voxel is damaged (so that holes in armor mean almost nothing), or equipment that breaks away random voxels as it takes damage but is 100% useful until 100% destroyed, or equipment that is 100% present until 100% destroyed with no voxel breaks at all.
This should also be balanced with a block limit or mass limit per item. This will prevent min-maxing the item by filling in the entire allowed area.
To encourage player-to-player combat, pilots should persist during ship flight instead of disappearing into the core. A capital ship can be neutralized by sneaking up behind the captain while he's piloting - and suddenly small, nimble, sneaky ships are useful against battleships. This also gives an extra purpose for hiring crews of NPC's (which will, of course, each need equipment created from the work-bench). Should the captain stop piloting and fight the boarded enemy, or hope his crew handles things and focus on the capital ship?
Boarding parties will be made easier by implementing teleporter pads (like warp gates, but for astronauts only). Ships that use teleporter pads to beam over boarding parties are susceptible to having the pad hacked by another ship and used as an entry point (though that doesn't mean they can't still use it to go out). Teleporter pads would also be more common if large ships can't handle gravity as well. It will also be useful for large ships that can't dock on a station. Then we have to decide; functionality vs. weakness.
Boarding a ship then gives cause for hacking systems (a power computer, a shield computer, a shield recharge computer, turret controls, dock controls, engine control, etc.). This would make boarding a ship a very effective combat strategy, and means that ships would have to acknowledge internal defenses (special turrets that only target astronauts) and ways to get computers back online once taken down.
The point that I am trying to make here is the importance of implementing astronaut mechanics while still developing ship mechanics so that they can be integrated as they develop rather than having to back-track and redesign. As it is going now, most game features discourage astronaut play.