Cannons : The kick back for a cannon should be related to the mass of the ship and the size of the cannon as well as it's position on the ship. Conversely, getting hit (if shields are down) should have the same jarring effect. Projectile kinetic energy should go up with distance not down like energy weapons heat damage.
Explosion damage: missiles and ship explosions should have a concussive effect. Ship explosions should have an associated heat damage proportional to the size of the ship. IE, if you're too close when it blows you are going with it.
Explosion damage: missiles and ship explosions should have a concussive effect. Ship explosions should have an associated heat damage proportional to the size of the ship. IE, if you're too close when it blows you are going with it.