No.
yes,ofcours they do!
Yes, humans hunt too many blue whales. Japan and Norway in particular need to stop whaling
Yes they are. They can harm them by polluting the sea. Humans have also been known to hunt them for skin and meet.
no animals that I know of hunt killer whales although humans do. (unless you consider humans animals then there is one animal)
no. gray whales do not hunt. they feed on krill.
Yes, the Inuit tribe has a long history of whaling. Currently they are only allowed to hunt bowhead whales within a certain quota.
Not many predators can kill whales, but small and young whales often fall as victims to killer whales, one of the top predators of the ocean. Humans also hunt whales for their body parts or for food, often illegally.
The Minke Whale has 2 enemies. The enemies are Humans and Orca/Killer Whales. Humans hunt the Minke Whales for their blubber and around 1,000 are hunted. Orcas feed on them as food but usually targets the more younger and more vulnerable minke whale.
Norway and Japan definitely hunt whales to kill them for food for humans to eat. Those two are probably the main ones but some other countries may do so too, such as Iceland and China perhaps.
As Killer Whales are actually whale killers, they sometimes lose their battle for forage against the very whales they hunt. But mostly it's us humans that have endangered them.
yes
yes and no