Except first order lever, both second and third order levers will not change the direction of force. Hope I have given the right one. I am not sure about the idea behind the question.
yes
Simple
Simple
Pulley can prove that simple machine changes the direction of effort.
Simple
yes
A straw is not a simple machine. Simple machines are mechanical devices that change the direction of a force. A straw does not redirect the direction of the force.
wheel and axle
Simple
Simple machines lets you trade force for distance, or the other way around. Or they change the direction of a force.
A compound machine is a machine that is made up of more than one simple machine. They they change the amount of force and the direction.
A dike is not a machine, it does not change the direction of any force or amplify any force, it is merely an obstacle to the flow of water.
No, a shelf support is likely a cantilevered beam, that is not a simple machine. Simple machines exploit leverage to increase or change the direction of force, a cantilevered beam merely supports a force.
An axel is a simple machine that relies on change in direction to make work easier. Furthermore, a simple machine is a device that makes work easier by increasing force or changing the direction of a force without electricity or other power sources.
Simple
Pulley can prove that simple machine changes the direction of effort.
Simple machines are things that change the direction or magnitude of a force. A bicycle saddle doesn't do that, so no.