A few questions? More like several, and some pretty fundamental questions at that.
What would happen if the electrons had stopped their motion?
Well, one might as well as, what if time stops, or what if all motion ceased? If electrons stopped, we'd have a lot of dipoles. The physics of the world would be very different.
When the elements react, do electrons change their motion?
In a sense yes. One has then to look at atomic and molecular 'orbits'. Electrons in combinations of atoms behave somewhat differently than electrons in a isolated atom, simply because the potenial field becomes more complex.
How do different elements affect the electrons of another element?
Some atoms are electropositive (e.g. alkali elements), i.e. they give up exclusive domain of their outermost (valence) electrons, while others (halides) are more electronegative, i.e. they readily capture electrons to fill out their outermost shell of electrons (I'm putting it rather crudely here). Alkali and halide elements form 'ionic' bonds. Elements which have similar electron affinity form covalent bonds where the valence electrons are shared.
Strong nuclear force combines quarks, but not quite protons to neutrons as far as I think. Do all 6 quarks produce a nuclear force connectring one each other?
In nucleons, the proton and neutron, there are only two types of quarks - up (u) and down (d) - and the proton is (uud) and the neutron is (udd). A neutron can decay into a proton, which is consider to be a transformation of a d-quark into a u-quark. See -
http://hyperphysics.phy-astr.gsu.edu/Hbase/particles/proton.html#c1
And the strong force is involved in the binding of quarks into composite particles (hadrons) such as mesons and baryons - http://particleadventure.org/particleadventure/frameless/strong.html
The residual strong interaction . . . is what "glues" the nucleus together
http://particleadventure.org/particleadventure/frameless/residualstrong.html - at least that is the theory.
http://hyperphysics.phy-astr.gsu.edu/Hbase/particles/hadron.html
What gives a property to a particle, like charge, mass, how to react, etc?
Nature. It is what it is. Nobody in this part of the universe was around when it got started, so we don't really know why it the way it is.
Was there space-time before the big bang?
We don't know, and we may never know.
May it be that the universe is endless although it doesn't agree with relativity?
Maybe, maybe not. Stay tuned to this network.
