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, a planeswalker is considered a permanent in Magic: The Gathering.
Yes, a planeswalker is considered a nonland permanent in Magic: The Gathering.
No, a creature is not considered a spell in Magic: The Gathering.
When a creature with trample attacks a creature with protection in Magic: The Gathering, the attacking creature can assign excess damage to the defending player or planeswalker, bypassing the protected creature.
Yes, planeswalker abilities are considered activated abilities in the game of Magic: The Gathering.
Yes, planeswalker abilities use the stack in Magic: The Gathering.
When a creature with trample is blocked in Magic: The Gathering, it can assign excess damage to the defending player or planeswalker if it has enough power to destroy all blocking creatures.
The trample ability in Magic: The Gathering allows a creature to deal excess damage to a defending player or planeswalker if it has more power than is needed to destroy the blocking creature.
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.