I was wondering how the species described below could survive in tropical, subtropical, and warm temperate zones and in mountains, forests, wetlands, deserts, open plains, rainforests and coastal areas. A species I have been designing are artificially created using terrestrial endothermic mollusks. They are externally similar to humans save for some liberties such as chitin and bony plates on their chests and forearms, depending on the variant, and they are very different internally, with a less developed endoskeleton and a digestive system closely resembling an octopus'. They range from 3 meters tall (very rare, only 1 to 3 thousand worldwide) to a meter to 122 centimeters two (extremely common, 5 billion worldwide).
They would have a circulatory and respiratory system similar to that of an octopus. Their minds would also function similar to that of an octopus' except for the numerous lesser neuron clusters in the tentacles. To elaborate on the skeletal system; it consists of an endo- and exoskeleton, with the exoskeleton covering the torso and forearms and the endoskeleton making up the spinal column, limb bones, finger and toe bones and the skull. Their tendons and ligaments are very primitive, being little more that particularly fibrous muscles. Their joints would be more fluid than that of a standard human and held in place by connecting muscles and joints locks, such as in hinge joints, but they would still allow a greater range of motion. The exception is in the hands, wrists, ankles and feet where the joints are very connected in a manner similar to ours.
Their skin has a structure identical to ours with the production of hair located on the scalp, brow, eyelids and, only in some subspecies, the face. They would have a largely identical facial structure to ours, save for the bones. They have a brain case, orbital cavities, an upper jaw that is fused to the brain case and a lower jaw identical to ours. Everything from the upper teeth to the orbital cavities is occupied by muscle and their inner ears. They have a sense of smell, taste and a nose that operates similarly to a humans. They are capable of respiring through their skin. They have no external ears and instead rely on the minute vibrations in their eyes produced to trigger bones in their mid facial cavity to move and then it operates very similarly to that of a humans. Their eyes are identical to that of a cephalopod's, save for that is focuses by changing the shape of the lens, like that of a humans. Their brains operate in a mix of human and cephalopod thought patterns and structure, which are already similar. They are omnivorous.
Edit: I have fixed the formatting. Also, I realize I made a mistake regarding height. I meant 3 meters instead of 9 for the tall subspecies.