Isn't Petrarch delivering the command briefs at that point in the game (when the player takes command of the 70th Blue Lions). I am absolutely certain one of the command briefs said something like that.
Petrarch almost always gives the Command Briefs, but starts giving the Mission Briefs as well when you get command of the 70th.
Beam technology was taken from the Shivans, or at least, presumabley
The Lucifer hulk, or what was left of it, is in the Sol system. The rest of the Lucifer was obliterated in Subspace. Granted, the GTVA most likely worked beams out from scans taken of the Lucifer while it was still on the war-path, but it can still be argued that the technology was entirely home-grown.
It makes as much sense as not using an M-16 in a jungle, and not using an M-4 Sherman in a swamp. The only way the Shivans got into GTA / PVN space in the Great War was through unstable nodes, as far as I know this makes perfect sense.
That's not true. We don't know they came through 'unstable nodes', the game merely mentions the Shivans
can use nodes too unstable for allied ships, not that they entered Terran-Vasudan space via one of them. Until canon says otherwise, there is as big a chance as any the Shivans came through a stable node that was simply uncharted.
Where would you prefer I get my information, if I wanted to I could say "the Lucifer's beams are orange, and most Shivan beams are red, this points to a fundimental difference in technology" but that obviously wouldn't make sense, the tech descriptions I consider accurate unless there's a specific ingame statment that says otherwise
Pnakotus makes a good point. The tech entries, while canon at their core, are riddled with inaccuracies and factual errors. One must always back up ones idea primarily from ingame chatter or briefings with support from tech entries, as theories constructed the other way around tend to be a little off-kilter.