Inertia makes it stay still and determines how hard it would be to get it moving
To remain static (still, not moving).
Mass
Inertia is the tendency of an object to resist a change in its motion. Objects with more mass have more inertia. The more mass an object has the harder it is to change its motion. Thats is how inertia effects and object. (Don't worry I got this from my Science Textbook)
By adding or losing eletrons (friction)
Static inertia is when a body at rest wants to stay at rest, or a body that is moving at a constant speed stays at the constant speed.
Assuming that the force is great enough to overcome static friction; the force will change the momentum of the object.
What kind of object in what kind of motion? The question is too vague to answer, and the forces depend on the properties of the object and its environment anyway. For example, there might ... or might not ... be significant electromagnetic and/or gravitational forces acting on the object (technically, any real object in the real universe WILL have electromagnetic and gravitational forces acting on it, but they may be insignificant in some cases).
mass/inertia, static and dynamic friction/ weight, air/wind, magnetism (in the case of a magnetic object in a magnetic field), ...
inertia is a plant
Weight
No. An object that has a lot of mass and is hard to move has inertia.
matter is not related to inertia. Mass is.