No. First of all, despite the common name of "killer whale" orcas are in fact dolphins. But also, many whales (including humpbacks, sperm whales, and blue whales) are the prey of the orca.
Yes they are called pods.
yes. all mammes are, exept for the platapus.
all over the world but mainly in antertica
Yes I believe they do but when going to give birth, they need to go back to warmer waters.