A week is no problem for fish that have been fed regularly, they should be able to go two weeks without feeding. Just do a water change and vacuuming the day you leave or the day before to make sure their water stays good while you're gone. Weekend or vacation feeder blocks foul the water more often than not, as do non-fish keeping friends who tend to over feed.
Unless you have live plants, the light is more for our benefit, the fish couldn't care less. Leave it off, a light with a switch like that is a fire hazard, but only when it's left in the "on" position.
Nice to see you posting again!