Yeah what a start.
I also taught the beginning will be slow, introduction style,...
But no, brains, brains everywhere.... Awesome!!
Ohh my God, the Gas mask Zombie dead was brutally amazing
About the infection:
I share your concerns, though I think that there might be an explanation for that later. I can't imagine storyplot hole like that in a universe developed like Walking dead.
For the scratches, little bites: it's not the wound that kills you it's the fever that will decimate you. Aka end of season 1. Though this still doesn't explain the bood on face, probably swallowed in very small quantities,....
Spoilers ahead don't read if not watched....
My guess is also that the newborn will be the first non infected human again. Just like HIV there is a chance the embryo is safe from the infection...
Also I would have cleared the prison in an other manor.
They have the overhand in the prison.
Go get a bait, animal, whatever, and lure the Zombies in one of the blocks and close it, pour some gasoil over them and watch unfold...
Ohh yes the famous rule about not burning Zombies to not spread the virus into the air....
Then there are so many other ways to clear a cell block, arouse them with water, a bit of electricity with a generator found in the prison, ...
No let's go in the dark hallways with no evac plan, not enough light and no body armour,....
Seriously with a bit of basic body proctection, a Zombie can't really harm you on sight.
Lumberjack suit, skate protecion, anti riot headgear, and a bulletproofed vest.
Also what's up with the small knifes, why go that close to a Zed when a baseball bat filled with nails would do the trick 2 feet away from the teeth of a Zed?