Minefield

Why do the Enterprise space suits shine huge blue lights into your face? Surely this would make it very difficult to see anything! Of course the real reason is that it lets us see the actor's faces without having to shine studio lights into the reflective faceplates, but reality doesn't enter into this...

That self sealing mechanism on the space suits sure is handy. You have to wonder why Worf's suit in First Contact didn't have it, given that his was over two hundred years more advanced than Reed's.

How come the Romulans have cloaking devices? Kirk and Spock were amazed at the technology in "Balance of Terror", clearly implying that the Romulans didn't have it in the Earth-Romulan war which lies just a few years in the future to Enterprise.

Why do the Romulans call themselves Romulans? I had always thought that this was just what Humans called them, based on the old legend about Romulus and Remus founding the Roman Empire. Yet the Romulans call themselves by that name to Hoshi. And clearly Hoshi wasn't translating it from some Romulan word, because she initially mispronounced it and T'Pol corrected her.