The inexperienced commander, Burke betraying them etc is all by the numbers, simplistic story telling designed to create drama but Cameron makes it work and that's all that matters really.
The whole space bug thing used to bother me because I felt it diminished the impact of the original creature. It was a little disheartening for me to see the Alien bowing down to a bigger, badder version and find it was just a foot soldier. I got over it though.
I much prefer Alien but Aliens is a great movie too.