When the hirogen hunter kicks seven of nine and she is struck back towards fixture in training you can see it's stunt double and not seven or actress Jeri Ryan's face in the shot.
The writing on the walls of the arena are actual Japanese characters for the word "Tsunkatse". It seems odd they read and write Japanese on the other side of the galaxy. e6d.
Seven is away from Voyager for much longer than her regeneration cycle. Despite this she never shows any of the ill effects associated with failing to regenerate.
During Seven of Nine's first fight, look at the shoulder of Dwayne Johnson when he says the line "I'm trembling." You can see a clear shadow from the boom.
The Doctor says of Neelix's Leola root ointment that "Talaxian homeopathy is no substitute for medical science;" however, The Doctor would know that "homeopathy" is not a synonym for "home remedy," and Neelix's remedy is not homeopathic in nature.