Despite being clearly the intention of the production, Quinn and Maggie do NOT land on the world the series started on - the garden door creaks, but it got fixed in Into the Mystic.
When the Sliders activate their timer in the catacombs, the vortex radiates a red light. Their vortexes usually emit blue light.
There are a number of errors; the pulsars approaching Earth are depicted as cylinders, with a visible rotation. In reality, the gravity field of a pulsar, also known as a neutron star, is so strong (not quite enough to be a black hole) that it can only be spherical in shape. Pulsars were spoken of as theoretical constructs, not only by the people of the doomed world, but by Arturo and Quinn; in this world, presumably the Sliders' home, pulsars were first identified in 1957. The plaque on the Voyager probe shows the location of Earth relative to pulsars. Even though their bodies are small, pulsars are so massive (an asteroid-sized pulsar actually has more mass than the sun) that there could never be a cluster of them - their gravity would coalesce them into a single body at that distance. Finally, the effects of the gravity of a pulsar entering the solar system, even if it was a hundred million or more miles away from the Earth, would disrupt the orbit of every planetary body, including asteroids and moons, to the point where Earthly life would probably die out long before a collision could occur.
There's a scene showing numerous corpses who were killed by the soldiers outside the base. The bodies show no bullet holes or blood.
Several people try breaking into the base and are shot dead. Later, another group tries to break in. Some of the deceased members from the prior group are in the new mob, even wearing the same clothes.
Finding a suitable new home for the survivors is a pressing matter, given the limited time available. However, everyone waits for Maggie to recuperate and join Quinn. Quinn could've continued scouting with someone else.