[@SomethingWitty]1) In the dream I based this on, we were raiding a temple to steal books on magic and scare the people there so that they'd be more resistant to the addictive effects of the priest's powers.  That will probably be the first mission.
2) It's just a mutation that spread through their population due to the small gene pool in the early years.  Some people think it's the result of breeding with spirits.  Their strength and size is just the result of natural selection in the harsh environment of the pre-terraformed planet. It possibly has something to do with protecting them from the planet's orange sun.
3) I'm not sure what I'll do with Earth yet.