All international flights require a passport, except for European citizens travelling between European countries, who only require a national identity card.
Internal flights generally require only government issued photo ID, such as a driving licence.
State ID or Drivers License
Yes. Did it today. After a quick screening
Yes.
yes
yes
ofcourse you do
It all depends on the type and size of airplane.
You can board it and you can also fly it.
Yes. Identification is not concerned with whether you are permitted to board; that was done at the checkin and ticket booth.
Airport
A spacecraft need a rocket engine (which is powered by on-board oxygen and fuel) to propel itself, an airplane only needs a jet engine (which only needs on-board fuel as it uses oxygen form the air).
Yes.
3 sandwiches