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.
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.
No, a creature is not considered a spell in Magic: The Gathering.
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.