Icebrand

No, even in JP. But someone in global already make it to +5 by buying recipes from shop.

62 million gil is a lot for one sword. Hopefully they are using it for Gilgamesh or Agrias in the future.

I would wait for Lesalia Guard's Sword which is from a future event. It's +Ice/slash attack and you don't need to craft multiple to +5. Just need to awaken to 5*

No

only increase the dmg on ice units or ice atks, so nasha for example can benefit for using it for her auto atks, while any red mage who can use blizzard could also.

It's a good weapon for Gilgamesh

Ice attack +30 fully awaken

You can buy more recipes so in theory you should be able to eventually craft a +5