QWhen playing this spell, does the spell itself count toward the condition "if there are at least 5 Academic cards in your cemetery"?

ANo. While you're resolving this spell's effects, it isn't in the cemetery yet.

QIf I have at least 5 Academic cards in my cemetery and an evolved Grea, Mysterian Dragoness on my field, does Grea's Ember deal 4 damage?

AYes. Its damage first becomes 3 from its own replacement effect, then gets increased by 1 by Grea's ability.