I believe its neither. The acting is on par with the writing, both are pretty amazing for the show. Fact is, Robb is doing the same shit Ned would have done had the roles been reversed. Plenty of the ideas are stupid but he's doing what he considers to be the honorable way to go about it.
While I do agree that plenty of things have been changed around from the book, most have stayed true enough to keep TV viewers interested. Just imagine Dany having the actual story from COK last season. How many chapters did she have in that book again? 5? Her screen time would have been even more non-existent than it already is. Robb's marriage is probably the best example because, as you said, in the books it made him sympathetic but on the show it really does come across like he just does NOT give a fuck what the Frey's will think about it. "I'm their king, they will get over it. I'll throw 'em a bone and give 'em my uncle instead."
As a long-time book-fan some changes have bothered me a bit while others are totally understandable. You can't fit in everything from the books, let alone keep the same stuff and trim it to fit in 10 episodes. Robb's story had to be changed or he wouldn't have much screen time at all. I don't mind it as I believe the books and the TV show are going to have their own canon. Plus, I like to be surprised now and then. I can't wait to see these boards by the end of the season. Gonna be so fun to watch, lol.