Aliens vs. Predator Requiem lingering questions

[Collectors Set]

So I am probably the last one, but finally got around to watching this BLU movie. The sound quality was amazing. I am well aware of the debates, issues, and criticisms. I am not here to rehash this as my take is simply from a beggar can't be chooser perspective. I am a big fan of this sci-fi genre stuff and was thrilled to get another movie. At least they greatly improved the appearances and physical structures of the aliens & predator for this one.

Here are my questions.

1. The coolest thing about this movie is that it picks up directly at the very moment the first one ended. But as things get hectic on that ship and the alien-predator pops out literally where are all the Predators?? There is only like a few. As I recall at the very end of the first movie, that ship lands on earth; and it seemed like there was a whole bunch of Predators coming out, as they lifted up the fallen Predator, load him on the ship and the highest ranking Predator is standing outside giving a "gift" to the mountain climbing female as a show of gratitude after he sees her war "markings" on her cheek.

2. I understand this lone traveling Predator who comes to earth looking for his comrade after the distress signal is obviously like the Michael Jordan of Predators. But after he assesses the situation here on earth and towards the middle realizes there is an infestation of Aliens, why not call for backup?? Why is it that the Predator is always alone or so greatly outnumbered in these movies?? I realize that his rep or street cred is built on that, but it would be nice for once to see a more evenly matched duel in terms of numbers.

3. When the Predator is walking underground looking for the Aliens in the sewer system, why not go to camouflage mode and get the edge when he was clearly so outnumbered??

4. The ending of the first movie was clearly a brilliant cliff hanger and you pretty much knew a sequel was coming. You could kind of say the same thing about this one as I doubt the Predators will want us having their technology. I double checked box office mojo and the world wide gross for this movie was $128 million dollars. Keep in mind, this figure is box office tickets only, so clearly it was a great return on investment for the makers. Do you think we get another one of these in the next few years??

http://www.boxofficemojo.com/movies/?id=avp2.htm