It doesn’t specify Santa’s turn, so you can use it every turn.
It’s a single sentence, so yes, treat it as one single ability for copy/cancel purposes.
No, a move action is required.
It’s not triggered by some outside action (like Loki/Thor, for example), so you can only activate it during your own turn.
Yes. Because they don’t have bows, any part can touch the island to dock.
No, only players opposing to the original owner can gain gold from Ransom, regardless of what happens to the crew.
Correct. The Eternal ship can be scuttled and repaired, and pinning will never trigger the endgame.
Treat the front point (dot) similar to the bow of a standard ship for movement purposes. It does create a big swing with the tentacles sticking so far past that point, but functionally it’s really not that different from a ship with a long front sail that reaches past its own bow.