The constitution does not require the speaker to be an elected member.
False! Alexander Hamilton was the Secretary of Treasure. Thomas Jefferson was the Secretary of State.
For Dictatorship, the second answer is incomplete, a dictator may obtain power not only through elections but by a military or institutional coup d'état, a civil war or a military intervention by a foreign power.
In a republic, power is held by those citizens that are able and government is a public matter (res publica in latin) to vote and the power comes from their vote during elections.
Democracy and freedom from post World War II Communist Russia.