I like that, though as you considered yourself swap fusion and plasma engines in table 41 and 70, and maybe put Grav drives as Astrophysics 1/Physics 2 which would slot it development wise between Ion and Fusion?
Maybe instead of Dual, Triple, Quad mounts a Multiple Mount, with Power, Tonnage & LP cost +50% and double cost per additional weapon, with each weapon allowing an additional shot.
hmm no thinking that through that's very exploitable. maybe a sliding scale second weapon is +50% third is +75% fourth is +100% etc that makes it not as efficient to keep piling on the weapons, or possibly leaving the 50% just making it cost more per additional barrel, like +100 for second, +150 for third, +200 for fourth