Assuming I had conjured the mind first, if I’m inside an Otiluke’s Resilisent Sphere, can I still cast spells as if I was in the mind’s space?

In narrative combat how would you handle cone attacks?

Can you elect to not hit a second target with Geen Flame Blade even if one is in range?

Does a cantrip only count as “cast a spell” then?

Does a cantrip only count as “cast a spell” then? A caster can’t use a cantrip on an opportunity attack?

Magic Missile 3 bolts. +3 per bolt or flat +3?