Yes, it is legal in the US to fly a US, or other flag, from your car. Many people do that.
Yes, Its legal to fly it in any state. It's your 1st Amendment right.
No flag can be flown the American flag when on American soil.
vessel which flag intitled to fly
Its a same way we fly a flag ay United State.
No as the U.S house of congress is a American state building only the The U.S flag can fly there.
vessel which flag intitled to fly
Any flag could, but it would be disrespectful.
Any state flag should be flown below or level with the US Flag, but never above it. If it is on the same level it should be on the right, this includes Texas. The rumor that Texas is the only state that is allowed to fly at level with the US Flag is just that a rumor and an urban myth.
Yes.
Fly you in an airplane, or drive you in a vehicle.
Pride and glory for the host.