Yeah I don't think it needs any drastic changes. Considering it's possible missile loadout (for either), burn drive is a good system for the ship. I just wish the AI would not cancel it so cautiously! Run your enemy down!
In terms of is 40 an overbuff: I would also say no. Comparing loadouts with an Onslaught as FooF mentioned, they are both 40 DP ships and yet the Onslaught can comfortably run a full stack of hullmods to boost itself, while a Legion has to sacrifice in one of its categories (fighters, missiles, guns) in order to afford the basic "required" ones.
40 OP seems maybe a bit much...
...Until I consider OP costs on bombers and what it takes to actually have both good direct combat power and not the cheapest fighters you could be fielding.
Though, hrm. Were it me doing the changes, I might, instead of the OP increase, go with a 10 point discount on fighter LPCs, similar to heavy ballistics integration for ships that might otherwise want to downsize some of their large guns? It's the same total bonus, but it also removes the current incentive to consider installing talons or mining drones...
Hmmm.... is it actually a bad thing to install talons or mining drones though? I feel this is a different situation as compared to Heavy Ballistics Integration: in that case ships have non-overlapping arcs of large slots, so its best to just "stack" up on one arc and completely ignore the other, which the hullmod fights. There was a net gain in power for ignoring half the ship with little penalty.
In this case though, if a player chooses talons or mining drones, its a choice to specialize that does carry a heavy cost because the weapon systems (fighters + whatever else) are deployed simultaneously. Its like a ship that has large ballistics in the same firing arc: HBI doesn't really make sense there.