No idea on 1, the common sense answer should be No, but SE's licensing process has been weird.
On 2 the answer is yes because of the aforementioned licensing wackiness. If you want to play Heavensward content on both your PC and PS4, you'll need two copies. Keep in mind that if you're buying collector's editions or digital deluxe editions, you only need to do THAT once. The other one can be just normal non-shiny edition Heavensward.
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svlyons wrote:
If random outcomes aren't acceptable to you, then don't play with random people.