Light is not wave or particle but vibrating EM force.

The electrons on your screen are connected with the electrons on your eyes right now and share their vibrating force so you can read my comment.

All atoms are constantly vibrating due to kinetic energy carried by charged particles within.

There is NO such thing as photon. Electrons repel each other with the force f=kqq/rr, that force is the carrier of radiant energy/light. 

Put strong magnet in both hands, same pole face each other, feel the repelling force/tension? yes.

Now wave 1 hand back and forth to the other hand, what do you feel?

That is the mechanism of light/em wave/photon/quantum.

Instead of magnets, all electrons in the space are connected by electrostatic force f=kee/rr. they repel each other all the time. any 1 is moving, all other electrons share the force according to distance.

That's why light speed and electrostatic force speed are the same. light strength and Electrostatic force strength are both decay at 1/rr.

Gravity speed and strength is the same. Why? Is gravity relating to electrostatic force?

Yes. Gravity is induced electrostatic force between neutral charged matters.