I guess there would be no incentive to mine like btc (which verifies transactions)
More energy would probably be focused on trading then mining. I am not sure how many bitcoiners mine but I am guessing the ones with the most resources since a newb normally wouldn't be able to afford to mine (and a small reward wouldn't be worth it).
I think it depends on the POS rate, if it was low, that would tip favor to mining and holding BTC would it not?