I was reading an article that said pulsars could be used in the far future, by travelers, by acting as "lighthouses" in space and aiding in interstellar travel. In a galaxy wide civilization, would this be still necessary or beneficial, if they had a method of faster than light propulsion?
The simple answer is yes. Even with faster-than-light travel spaceships will start from a position below lightspeed they can use the pulsars to orient their direction of travel and initial location. Assume they travel the distant for their voyage, when they are again below lightspeed the spaceship and its navigation systems will be able to determine where they are.
This assumes while in FTL mode spaceships cannot 'observe' the pulsars. If spaceships could 'observe' pulsars while in FTL motion then navigation is much easier.
Essentially pulsars are excellent natural navigation beacons. They can be readily observed effectively anywhere in the galaxy. Each pulsar has a distinctive frequency and they have known positions in the galaxy. If a spaceship had shifted one thousand light years (assume it has used a jump-drive to instantaneously move), then by measuring the positions and frequencies of the reference pulsars it is suing for navigation it can determine where it is in relation to them and how far it has shifted. This is essential if the jump-drive in this example isn't accurate in where it materializes and a course correction is necessary to arrive at its destination.
In summary, if pulsar navigation is useful for sublight, interstellar travel, and pulsars most certainly will be, then it will be equally useful for faster-than-light travel too.