The Robinsons Were Here - S1-E4
Continuity mistake: Penny is holding an envelope in her hands, then turns around to follow the siblings and the envelope is gone. Just a cut later Penny has the envelope back. (00:32:30)
Pressurized - S1-E7
Continuity mistake: When Judy is trying to keep Evan alive in the vehicle, sometimes there is a seat belt across his chest, and other times it is gone. (00:28:00)
Continuity mistake: Don West is wearing Dr. Smith's necklace, even though it was lost in the storm. The necklace is then not there or removed in the next shot. (00:31:30)
Trajectory - S1-E8
Continuity mistake: When John is under the panel with Will, right before Will hands him the flashlight, the way Will is gripping the flashlight changes between shots. His pinky is either on top or underneath.
Answer: Yes to all questions. The best theoretical estimate is that the universe is about 7 trillion light years across. That is about 250 times larger than the currently observable universe. So, yes, using trillions of light years as a unit of measure is appropriate. And, yes, the age of the universe is a measure of time, and the space between galaxies is a measure of distance.