Here's me opinion.
New ships
It's been hinted at that new ships are coming out later this year. I have all the war ships, yet there is nothing I want more than a big ol' SOTL. New ships will come out at some point, but we just don't know when.
Customizable Ships
This update should definitely be added to the game. Disney haven't said anything about adding it in, and we may have to wait a few more years for it, but a pirate isn't a pirate without a unique ship. 'Nuff said.
Pets
A thousand times no. The idea is good, but knowing Disney and what they've done with pets in games, they're most likely going to be noisy and really annoy other players. I wouldn't be surprised if you could make your pet sing, if it ever came out. The Summon Chicken potion is a good idea though, and I heard that more were going to come out with different animals. I think that's as far as Disney's going with the pets. At least I hope so.
Raven's Cove rebuilt
Um, no. Raven's Cove is still one of the newer islands, and I don't see why it should be rebuilt. There's nothing really wrong with it, in my opinion. I quite like it as it is.
Open sea and land PvP/SvS
Well, SvS is already open-area, but there should be a PvP island, full of angry pirates. :P
New Treasure Maps
Now that you mention it, I think new treasure maps might be quite cool. Good idea, but I'm not sure if Disney could make anything better than the Black Pearl Boss Battle.
Real Treasure Maps
I don't think anybody's thought of this before. It's quite a good idea. It would be like a quest, but you do it alone. And the treasure could be something very rare, like a weapon, clothing, or a lot of gold. It would end with you digging up a chest. Sounds piratey. I like it.
The first two updates on your list are the most important to me. I agree with some of the rest, but I feel that new ships and ship customization are a must.