If the sun disappeared then absolutely nothing would happened for 8 minutes as it takes 8 minutes for both light
and gravitational forces to travel to Earth. After those 8 minutes it would suddenly look a lot like a night. There would be no sunlight to illuminate the moon or other planets, so you wouldn't be able to see them. It would also start to get cold. If the temperature drops around 10-20 degrees at night, depending on how cloudy it is, I guess the temperature will be dropping around the same rate every 8 hours, so within a day it will be well below freezing and within a couple of days we'll all be dead.
The instant the gravitational force from the Sun has gone the solar system as we know it will cease to be. All the planets will just travel in a straight line in the direction they were going at the time the gravity stopped never to return. The moon will keep orbiting in the same way as it is trapped in the Earths gravitational pull.
As far as photons getting sucked into black holes goes. As I understand it photons don't have mass, but they do have momentum (the mass component calculated from E=m*c*c). So if they don't have mass why do they get attracted to heavy bodies? All mass slightly alters the shape of space-time around it. Heavy object alter it a lot more and the black holes you are refering to are unfeasable massive. Light when moving always follows a straight path through space-time, but if this space-time is curved through the presence of a massive object then from our perspective (we cannot see space-time) the light appears to bend its trajectory towards the heavy object.
Oh and the speed of light is fixed for a given medium. Light travels at different speeds through a vacuum, through air, through water etc. The
slowest speed of light measured with light passing through a supercooled Bose-Einstein condensate of Sodium atoms was a whopping 38 miles an hour.
