Yes, a planeswalker is considered a permanent in Magic: The Gathering.
Yes, a planeswalker is considered a nonland permanent in Magic: The Gathering.
No, a planeswalker is not considered a creature in Magic: The Gathering.
No, a planeswalker is not considered a spell in Magic: The Gathering.
Yes, planeswalker abilities are considered activated abilities in the game of Magic: The Gathering.
Yes, an enchantment is considered a permanent in Magic: The Gathering.
Yes, planeswalker abilities use the stack in Magic: The Gathering.
Yes, in the game of Magic: The Gathering, a land is considered a permanent.
Yes, a planeswalker can be your commander in a game of Magic: The Gathering if the format allows it, such as in the Commander format.
No, you cannot block with a planeswalker in Magic: The Gathering. They are not creatures and cannot be used to block attacking creatures.
Yes, in the game of Magic: The Gathering, you can target a planeswalker with a spell or ability.
Yes, in the Commander format of Magic: The Gathering, you can use a planeswalker card as your commander.
Yes, planeswalker abilities count as activated abilities in Magic: The Gathering.