Why does cover work like this in 5e?

If a creature is under the Fear spell but in the Aura of Conquest…

In the 6th printing of the PHB vehicles are listed on the tools chart. Are vehicles considered to be a tool?

Extra attack: as a fighter, the “extra” attack does not get my ability modifier added to it without two-weapon fighting?

What sorts of college classes would you recommend to someone looking at a future in game design?

In the case of a Half-Orc or Barbarian’s brutal critical, are these dice applied before?

For 5e what was the reasoning behind an unconscious creature still getting their Dex bonus to AC?