Nvm about the inertia tech. I thought I had sites to support me, but it's been a while.
For the self-replicating missiles, there is a Von Neumann machine that is able to replicate itself. The resources it needs is from the exhaust that is recycled. To make the proper materials to make the missile, the mother missile changes the atomic structure of the molecule or atoms, in order to get the right type of materials needed. A compressor is added so the missiles can be the same size. The mother missile collects space dust or any stray matter that is detected on the way to the target. A thin layer of armor and a small shield is also put into the missiles for a bit of protection. It takes 5-15 seconds, depending on the resources available. Each mother missile is filled with enough materials to construct 4 more missiles.
For the orbs of energy, the energy is locked onto an enemy or a group of enemies. It will split up into smaller orbs as needed. The orbs would be small enough to conserve energy, yet big enough to kill efficiently. The smallest orbs are for the smallest enemy units out there. A single orb can kill a fighter. A bit bigger orb can kill a corvette. A bigger orb can kill a frigate. The biggest orbs, the ones that are created before they split up, can cripple a capital class shield. If the target is a capital ship, the orb does not split, for maximum effect. If the target is a frigate, the orb splits up to kill said frigate. The remaining part of the orb is used to kill frigate class ships or smaller. How much an orb can kill depends on the ship class. If a Keeper shoots the orb, the orb can take out several hundred fighters. Dreadnought's would be able to kill several thousands. Sajuuk's would be able to kill several hundred thousand and possibly a million. Though, the process takes up a lot of energy, and requires a minimal charge of 1 post, if it is a big orb. Smaller orbs can be created quickly.