small tweaks to parts plus a longer range weapon.
I am a big fan of Space Engineers and have been for a few years now, however I think that some small tweaks to the game might be needed to balance parts of the gameplay and make it more enjoyable. I suggest:
Buff safe zones. For anarchy multiplayer servers, they should be the first line of defence, but because zone chips are so expensive, it takes so long to get the money for enough chips to last between sessions that there is no time to further progress in the game, forcing players to sacrifice defence to gain resources. I suggest making the sale price for zone chips cheaper.
Nerf large warheads and buff small ones. The imbalance in these means that if someone wanted to make a hard-hitting missile or torpedo, they would have to use a rotator or connector to attach a large warhead to a small body, which makes printing much harder and can induce bugs. I suggest making smallgrid warheads stronger, or making the number of warheads connected to each other increase the size of a single explosion, granted they are all fused for the same time or all primed. This would come with a nerfing of large grid warheads, especially in the terrain damage aspect.
Add a new weapon. I can imagine this would be a popular suggestion topic, but I think a new weapon may open up more combat possibilities for the game. In its current state, weapons are focused around defence, having a range of just 800m and a focus on destroying lots of lightly armoured targets. I think that a tank-style cannon would be the best edition to Space Engineers' arsenal, having an explosion size of slightly less than a current rocket ammunition, but dealing more damage to heavy armour, with a projectile which travels at the speed of a gatling gun's bullet, and having an effective range of 3km (although the turret could only aim to 800m.) This extension in range would move the combat mechanic towards offence as well as defence, which would allow for large ship-to-ship combat.