It's all character stuff which you get in the books, though not necessarily in the same place e.g. Rob. If they skipped it out you'd lose a lot of it though.
Not much of a spoiler but:
For example Rob fucking his wife scene is meant to make you see and feel something for the couple before a certain event. Besides, she is fucking hot.
As for Tywin, it's just yet another demonstration of how much control he has over everybody within his arc. I personally loved that scene because Tywin is one of my favourite characters. Danny and the Yunkai was a nice scene as well because it finally shows her as something of a Queen. I've been getting tired of the annoying yelling that she always does every episode 'I AM DAENERYS STORMBORN OF THE HOUSE TARGARYEN AND I WILL BLAH BLAH BLAH'. It was nice to see a glimpse of her in the role she's going to spend a lot of time in now, which in my opinion is much better.
Nice episode with a good climax at the end (bear fight).
But I'm really sick of yet another "Theon gets tortured" scene. He gets way too much screen time and that story arc is even pretty much irrelevant until a certain person comes to the North.
Yeah they at least make it interesting though
Also I think the point is to let you know just how fucked up the bastard is. Because in the books it kind of tells you all the stuff he did to Theon post events. Which doesn't really work to well in a TV show, so to do those events now makes some sense. Although I think they are spending a little to much time on it, but that's probably more for the actors sake.