That is correct.
So if you pay 60 points you are going to get all of the Tzeentch minor power.
(Some people do that so they have have #4 Reckoning of Tzeentch guarantied)
I do believe that it is implied that you do not reroll ones, as the others all state that you do... I mean, is it also therefore that Thrall wizards have a toughness of 1, Predators have an AV of 12 (It's 11, folks), and an entire Raptor Squad may be upgraded to A SINGLE Aspiring Champion? They're called misprints and oversights.
No, Bolt of Change does not count as Daemonic Gifts. It states specifically that Gifts of the Gods count as Daemonic Gifts, EXCEPT PSYCHIC POWERS. Guess what folks? As already stated (C'mon now, say it with me!) "Bolt of Change is a Psychic Power."
Also, if you wanna pay 60 points, just to get that one minor power, you go RIGHT ahead, as I buy another entire squad of Guardsmen for that....