(However, if it's still in the graveyard at that time, it will count itself, as it is very much a hot card.) If another effect modifies how much damage your hot source would deal, including preventing some of it, the player being dealt damage or the controller of the permanent being dealt damage chooses an order in which to apply those effects
Earlier in the format, while mana is clunkier, its going to be stronger to punish less refined decks that are more interested in playing powerful cards than they are in having a cohesive gameplan, and Spell Pierce is better at serving that purpose than Dive Down is
Of course, youll need to reveal your deck contents to your opponents, but who cares
Its completely normal for a single turn to be composed of ten different actions that build on each other just to get a single pokemon evolution, for example, which sounds annoying but is satisfying in practice