3, 116, or anywhere in between
Yes, if you have turned your planeswalker into a creature, and it came into your control the same turn, then it will need haste like on Sarkhan, the Dragonspeakerto tap and attack, since it is sick from summoning
If it becomes night, the only mechanical changes that take place as the Stowaway becomes the Seafaring Werewolf are that the creature's power increases by one and its color changes to green
If any of that appeals to you, youre probably drawn to building a Boros deck
This could be two of each or just four copies of one of them
Backgrounds are customizable enough that theyre mostly all useful when paired with the right commander, though this one probably wants a partner that explicitly cares about or creates artifacts