Azorius decks tend to be exclusively reactive and defensive, using cards like Teferi, Time Raveler and Supreme Verdict to prevent their opponent from building any momentum
Legality depends on the tournament format -- Spellbinder can be legal in some formats and banned or restricted in others
It's up to the store whether you have to play a game in the store with the deck rather than just take it away
Fatal Push has become Dismember, as it is easier to cast and not susceptible to Chalice of the Void on one at the cost of possibly losing to Lavinia, Azorius Renegade and the now restricted Mental Misstep became Imperial Seal, a sorcery speed Vampiric Tutor that helps to elevate the decks consistency even further
There are no automatic triggers, no stack reminders, no alerts when an opponent's attack hits a threshold that should trigger one of your abilities
Also, one-mana spells like this make it easier to use removal and cast a creature to enable Celebration effects, unlike costly burn spells like Cut In or Taken by Nightmares