I think this is all good. A few things I would like to add.
1. Because building your own ships and bases is core to the game you cant just nerf voxel armor and not get massive voxel cubes. So I would leave voxel Hp the way it was based on mass and instead add a lot more resistances to the half tier voxels like Plastic Steel Carbon fiber exc like Plastic should be 90% resistant to electromagnetic but 0% to Kinetic Exc for all of the voxel you have the resistance mechanic in the game use it. Then nerf voxel by boosting weapon damage 2x or more.
2. To deal with lag reduce the number of weapons a seat can use so there all the same as Railguns just make weapons that are supposed to shoot more shoot faster or do more damage or hit with a burst of impacts like a 3 barrel cannon shoots calculate hit/miss if hit do 3 hits from the one shot if miss nothing more needs to be done reducing lag.
2. Make all weapons have the same range no matter the sized. So the XS Railgun and the L railgun should have the same ranges. So range changes by type of weapon not size. But like Engines make the Tracking be what changes with size XS have near perfect tracking L have very slow tracking. Because we make are own ships weapons meant for a size of construct cant be balanced so make them for attacking a type of construct like a real weapon would be designed based on what it needs to kill. Remove the weapon restriction by construct size so large weapons can go on XS Cores again.
3. Shields should recharge during combat every 30-60 seconds or so with a fixed amount of health and a shield should always negate all the damage from a shot no matter how powerful it is or how low the shield health is so no ship can be taken out with one shop this is why super small ships that can dodge 95% of hits still just die to the one L weapon shot that hits them.
4. There should be different types of shields with different resistances so that switching shields and damage types matters make a shield operator seat that can turn shields on and off and change resistances every 30-60 seconds the delay so that the server can have time to update to all the clients new hp and resistances.
5. Now that we have shields remove the fixed dodge chance from core size and add it to shield size so there is a reason to pick a smaller shield size, and let ramming do damage if the shield generator is off.