Interesting speculations... This book does go into Burke's motivation, and how much the Company did or did not know, and a little bit on how they operate. It's not all spelled out, but most fans will get the inferences.
As to the weapons discussion, remember that the report comments on footage/uploads/stolen files that the Company has gathered about this species. They (WY) have more information about the weapons used at Hadley's Hope, because it was a Company installation and transmissions continued at least until the processor blew; plus, the Marines would have received uploads from the APC, the drop ship, the Sulaco, and Bishop. There are newer weapons, of course, but they weren't designed to handle these particular aliens and have not been field tested... Unless you count the crappy guns that the USM used in Resurrection, which obviously weren't particularly effective (they are mentioned, though, briefly). This book was written post Res, and has transmissions and uploads and data from each movie's time period.
I did my best on details, but I'm sure not every question is answered, nor every pet theory validated. I am also a fan, though, and took this book quite seriously, and I hope that shows in the writing. Is it new forever-canon? Or free of mistakes? Not possible logistically, IMO. But it's a respectful, entertaining addition to the universe, and I don't think fans will be disappointed. Of course, I'm biased, I got to see the layout when I did the captions, and it looks very, very cool.
BTW, my dad totally never sang for Journey. But don't stop believing.
