a couple of rules questions about spreading seas manland magic

[Berserk]

If I cast Spreading Seas on a manland such as Ghitu Encampment, can the land still be turned into a creature?

If I cast Spreading seas on a manland such as Ghitu Encampment while it is already in creature form, does it remain a creature indefinately or does it immediately go back to being a land or does it only go back to being a land at the end of turn?

[Arix]

When a land becomes enchanted with Spreading Seas, it loses all of its abilities (including the ability to become animated) and gain the ability to tap for blue mana.

If you enchant an already-animated land, it won't stop being a creature until the end of the turn.