Any chance we might see some of the temporal agencies used by the other powers? I smiled when I read about the Temporal Assessment Group being mentioned since I really liked the LUG "All Our Yesterdays" Sourcebook. That combined with the Chronological Defense Corps was fascinating to me about competing agencies over time travel.
's set too early for that.
Should i watch every time travel episode and movie for the book?
Only if you really, really want to. Everything you need to know to follow the story is explained in the book. As a rule, you can assume that's always the case. It's not like we're deliberately trying to confuse or exclude our readers.