Point 1, laser cannons are stated to strike at the speed of light.
"Ten seconds," Han told Leia and Dorja, and reached for the triggers to the concussion-missile tubers.
Anticipation drew a metallic streak down his tongue. He felt a prickle of sweat on his scalp.
"Five." he triggered the first pair of concussion missiles, knowing that unlike the laser cannon, they did not strike at the speed of light."
"Two." Han triggered another pair of missiles. The Millenium Falcon's engines howled as they fought the pull of the dovin basal's gravity.
"Fire." the dovin basal swept past, and suddenly the display lit up with the six approaching coralskippers. The combined power of the eight turbolasers ifired straight at them.
The six coralskippers had also split into two Vs of three craft each, the formations on slightly diverging courses, but both formations were running into the Falcon and her armament at a combined velocity of over ninety percent of the speed of light. None of them had shifted their dovin basals to warp space defensively ahead of them, and the pilots had only an instant to perceive the doom staring them in the face, and no time to react. The first vic ran right into the first pair of missiles and the turbolaser fire, and all three erupted in fire as their coral hulls shattered into fragments.
(ref: Destiny's Way)
Point 2, missiles are faster than coralskippers(stated in Rebel Stand), it would logically have the most speed of the two, but a low-end figure can be gained by dividing the speed equally, wich gives us .45c velocities for the concussion missiles, so much for unsubstansiated notions of SW missiles not being capable of reaching such velocities.
The high-end version would have the coralskippers going at .1c wich is more likely due to reaction times of the pilots, wich means the missiles would be travelling at .8c instead.
Point 3, Yuuzhan Vong plasma weapons, on coral skippers are said to fire kg's of hot plasma, they are mostly comparable to turbolasers, no range advantages in tactical situations has been given to turbolasers either, strongly indicating that the YV plasma weapons fires kilograms of matter at high fractions of C, and infact, Coral Skippers can accelerate to fractions of C as we see, their weapons would at the very least be fired at fractions of C too to be usable.
Check mate I believe for the arguments that SW is somehow supposed to be extra vulnerable(for whatever unknown, unsubstansiated reason) to KE weapons.