Is the intent that only melee weapon attacks can knock foes unconscious?

What happens to a character with the Fly spell if he is incapacitated?

Sage Advice: Master Sage Jeremy refers to “Flying Movement” at p.191 that specify that Fly spell (or similar) can hover creature if are incapacitated. Fly spell is in the PHB p.243

Can you make unarmed strike even if you’re also wielding a weapon?

Why is the Death domain in the DMG? PHB has both assassin and necromancer

Most wall spells describe that you can shape it anyway you want. Wall of fire just states the wall or ring shape. Can you shape the wall like an L for instance?

Bard question: If I take a cantrip with Magical Secrets, does it count toward my total cantrips known and do I get an extra spell known to play with from the Bard list?