How does the Monks Radiant Sun Bolt interact with Spell Sniper?

War Caster hitting with Booming Blade when an enemy leaves its reach: can the enemy stop to avoid the extra damage?

Swashbuckler strikes with a whip, 10′ away… Rakish audacity sneak attack?

Can you twin spell with Green-Flame blade?

Booming Blade, did you intend for standing up from prone to trigger the extra damage?

Are Booming Blade and Green-Flame Blade compatible with extra attack?

Would an arcane trickster using Green-Flame blade be able to benefit from sneak attack?

We’ve seen the crest of Elturgard in the Sword Coast Adventurer’s Guide, but what would the colours of it be on a flag?