We get one card of each color with cheap mana costs and effects that will make you say things like, Oh that is SUCH a blue card. Spell Pierce is a one-cost blue instant that counters a noncreature spell unless its controller pays two mana, making it one of blues most useful spells in the early rounds
A Head Judge of the tournament may permit using Alpha cards without sleeves if your deck consists only of Alpha cards
Plus, Double Masters 2022 has marched plenty of prices down a cliff
Ok, admit it
If the card leaves your hand, it's too late: If your Miracle card happens to get bounced, exiled, discarded, or otherwise removed before the triggered ability resolves, tough luck, you can no longer cast it for its Miracle cost
Once you announce that you're casting a spell or activating an ability, players can't take actions until you've finished doing so