Cast spells as if they have flash - does it affect equipping?
No.


  307.5. If a spell, ability, or effect states that a player can do something only “any time they could cast a sorcery,” it means only that the player must have priority, it must be during the main phase of their turn, and the stack must be empty. The player doesn’t need to have a sorcery they could cast. Effects that would preclude that player from casting a spell or casting a sorcery don’t affect the player’s capability to perform that action (unless the action is actually casting a spell or casting a sorcery).


So in other words, "any time you could cast a sorcery" is just short-hand; it doesn't actually mean "casting a sorcery is a thing you can do right now". It means that the timing rules for that ability follow the normal timing rules for casting a sorcery.