The ShiftstonedEternal Power Calculator is a deck-building tool that visualizes your odds of drawing enough Influence and Power based specifically on the cards found in your deck.
Not sure, I haven't played this deck (or eternal) much after the nerf. I am now trying to play Ozio to replace Voidbringer. Vanguard should still be good but I am not sure if it is more competitive to skip the pledege package and play more interaction and Dread as the only pledge card.
No, destiny is a Skill (which include echo, destiny and ambush and all battle skills). Battle skills only matter on the battlefield. Non-battleskills include also warp and pledge but crown doesn't give those as they are useless after the unit is drawn and it is not somehow still turn one.