TV Lori vs Comic Lori

I'll start by saying the pilot is so great, absolutely thrilling. I think the show did a better job of showcasing the drama of a zombie apocalypse than the comic, but obviously that's going to be the case when you have a realistic depiction of the world rather than text bubbles and sketches. I feel like Robert Kirkman used the show almost like a fresh start for his story, a way to fix some things that he would have liked to change looking back. I preferred Rick's first encounter with the walkers in the show more than in the comic, the way the fingers started reaching for him through the chained door, rather than him stumbling upon dozens of them just gathered in one room, although that seems more realistic honestly.

Anyway, I could go on about my many opinions but I'll get to my main beef which is, as my title suggests, Lori Grimes! She's so sweet and simple in the first volume of the comic, I liked her. She seemed more like a woman struggling to come to terms with an apocalypse and the apparent death of her husband than a bitchy termagant who has abandoned her husband in favor of his best friend. I don't like Shane in the show for some reason, he's just the archetypal man's man, kind of a womanizer as far as I can tell and yet everyone loves him! Because he's handsome and clever and capable I can only assume. Everyone overlooks the fact that he wants to kill his best friend so that he can take his place as leader of the pack and take his woman and son! Also he was just a danger to the group, and didn't care about anything in general. I wonder at the show making Lori the bad guy at every turn, absolutely everyone was glad when she died, even myself, but you can't deny that she was a stone cold fox. Alright it's almost midnight I've taken some benadryl and my thoughts have become rather disjointed, cut me some slack.

Questions:

Why is Lori so hated compared to Shane?

What were Rick and Lori's marriage problems? Did the apocalypse solve them?