Killer whales, orcas, are toothed whales, but they're not the only ones.
No killer whales are not the only toothed whale.
no
The only kind I know about are killer whales.....
No. There are also Belugas, Beaked Whales and Bottle Nosed Whales among others
It largely depends on the whale. Toothed whales (such as the Sperm and Killer whales) are usually considered to be apex predators. Due to their size and hunting strategies their only main predator is humans (who are usually disregarded from such systems). Baleen whales (such as the Humpback and Blue whales) cannot be considered such as, though they are often protected by their immense size, their young are regularly hunted by other large predators, especially the toothed whales.
Blue whales belong to the Group of baleen whales - filter feeders. There are other baleen whales, but only one Blue whale.
Baleen whales and toothed whales are two DIFFERENT kinds of whales. A whale can only be either-or. Baleen whales are filter feeders, they eat a "soup" of small stuff they filter out from the sea. Toothed whales eat things big enough to catch one by one, or to bite chunks out of.
Humpback whales don't usually attack other species of whales. Killer Whales are the only whales known to do that.
No, Beluga Whales, and Killer (Humpback) Whales might become extinct.
Yes killer whales are almost extinct there are only 7400 left.
Killer whales will eat ringed seals but they are technically whales in name only. They are more properly categorized in the same family with dolphins and porpoises. Baleen whales (like the blue whale) eat only plankton. Toothed whales (like the humpback) might eat a seal but are more likely going to stick to eating giant squid and the like.