In Thailand we currently know of 11 species but expect there are certainly quite a few more than this. Probably the best known scorpion in Thailand is the large "Forest Scorpion" (Heterometrus spp.) In the world there are approximately 1100 species.
Scorpions have a wide variety of habitats ranging from very dry and hot deserts to moist tropical rain forest. Scorpions can be found in these habitats in a wide variety of places too, such as under logs and leaf litter, under bark and in burrows in the soil.
Again a detailed answer depends on the species. But generally scorpions are generalist predators preying on almost anything smaller than them that they are able to catch, however there are some scorpions that seem to be more specialist predators, such as some African species having a preference for millipedes.
Wow that is difficult. In reality there is no 'typical' behavoirs but a wide range so behaviors associated with species and even individuals. The most general sort of answer I can give is that scorpions are typically predators and many species prefer to hunt nocturnally. They are typically solitary creature in the wild.
Scorpions have male and female (like many other, but not all animal) and they must mate in order to reproduce. Mating is interesting as it typically involves a 'courtship dance' where the male scorpion deposits sperm onto the ground and then dances with the female, luring her over the sperm package which she then takes up. Some time later, perhaps as long a year in some species, the female will give birth to live baby scorpions that then travel around riding piggy-back on the female for some time before dispersing.