I agree with your points. The pacing felt slow as a glacier and mildly masturbatory in how pretentious it was. The dialog between the female guardsmen and the Sister of Battle, god damn it, it was soooo halting, and paced so awkwardly! Other little things were just weird as hell, like the Space Marine landing vehicle (thunder hawk?) spinning horizontally like that as it was crashing completely ignores wind resistance, and straight up wouldn't happen that way.
I did very much like how the 4 legged Necron lord was portray ed though, his movements, and voice were very well done and will get me to watch episode two. The Deathmark was very interesting too, but holy shit, this thing felt like it was made by a 1st year college student.