We now knew that while photons have no mass, they do possess momentum (so your statement about light not
affecting matter is incorrect).
This means that as a ship travels faster and faster towards the speed of light the ship is occupying more space every moment where the build-up of particles creates a gravitational effect upon the ship itself which would include light as well since light does effect matter. Meaning that since light occupies more space than any other particle where the light photons are traveling at the speed of light a greater mass of light photons is encountered by the ship more than particles which then causes an extreme amount of gravity to be produced by all of the particles and light photons and the ship itself that based upon this
As a the time and distance between point A and B contracts or gets smaller as the ship accelerates to light speed velocity, the gravitational field at the surface, or flight path of the ship gets stronger due to interactions between the particles and light photons encountered en mass, thus reducing the velocity of the ship and causing more fuel to be expended. This makes it more and more difficult for the ship to escape the collective mass of
encountered particles and photons. Eventually, if the ship reaches a critical velocity, the gravitational field at the surface becomes so strong that the path of the ship is congested so severely with the mass of particles and photons that the ship can no longer escape and returns to a normal velocity based upon the ability of the ships engines to effectively produce enough momentum to break free of the accumulated gravitational forces between the ship itself, particles and light photons.
So when designing the warp ship we would first need to figure out how to divert all forms of light photons away from the ship to reduce the amount of light that is absorbed by the material of the ship itself.
http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/961102.html