Hi there!
I've both watched the show and read the books and can say that I totally understand where you're coming from. One largely unavoidable failing I've noted in the show is how they have to condense everything, both in terms of characters as well as time. In my opinion, they do an admirable job of juggling concurrent events and consolidating disparate character arcs, but to a fan of the books like myself, that still gives one the impression of some rather frantic pacing. As you've already pored over the wiki info, I'm going to provide an example from a later season of the show that illustrates precisely what I'm talking about, as well as highlighting a "character consolidation" that fell well short of the mark in terms of the tragedy presented in Martin's books.
Here there be Spoilers!
In the books, Rob Stark's war with the Lannisters is far more drawn out, consisting of several clashes between the men of the North and the Lannister's field commander Gregor Clegane. Even though the reader isn't privy to every single battle, the impression is nonetheless conveyed that Rob's forces, once past the Trident, are very much an occupying force in the Riverlands with skirmishes both large and small happening with a great deal of frequency as Clegane and other loyalist to the (Baratheon/Lannister) throne seek to draw the Starks out of the relative safety afforded them in the lands held by their allies, the Tullys.
Far earlier in this series of battles, Rob Stark suffers a minor wound(during the capture of Jaime Lannister, as I recall) and is recuperating at the holdfast of some lesser lord. While there, he receives word of Theon Greyjoy's betrayal and the "deaths" of his younger brothers, Brann and Rickon, at Theon's hands. In his grief, Rob finds comfort in the arms of this lesser Lord's daughter, resulting in her pregnancy. Rob, in service to what he feels is the honorable thing to do in the circumstances, marries this young woman in spite of having already promised to marry one of Walder Frey's daughters as a part of his "payment" for passing his forces over the Trident via use of Frey's fortified "toll bridge," the Twins.
In contrast, the show has Rob simply toss aside his word to Frey(and some would say his honor), having fallen in love with the Volantene nurse, Talisa. Not only did this alteration in the plot rob us(pardon the pun) of his recuperation period and the protracted campaign of battles being waged in his absence, it also, in my opinion, sapped any vestige of honor from his actions. While I'm sure that some would argue that there is nothing more honorable than following the dictates of one's heart, I don't feel that this is the message that Martin sought to convey via Rob's character arc. It's supposed to be tragic. He, like his father, marries not for love, but for duty and honor. He, like his father, has to weigh his course of action and balance as best he can duty against honor. And he, like his father, pays the ultimate price for attempting to strike a balance between the two.
As far as the hurried pacing goes, the events recounted above also serve as a workable example of how the show, almost of necessity, has to take a great number of liberties with timing and pacing. By jumping from setting to setting in an attempt to keep their viewers abreast of developments far and wide, they never got to focus on the so-called "War of the Five Kings" sufficiently. We hear about the lawless chaos into which the Riverlands have descended largely second-hand. We only see the merest fraction of it through Arya's and Gendry's brushes with the "Brotherhood without Banners," Brienne's and Jaime's trek to King's Landing, and Brienne's subsequent quest for the remaining Stark children. We aren't witness to the atrocities all sides are committing. We aren't made aware of the fact that, without a king to follow, a great many of the stranded forces from the north turn to pillaging across the Riverlands, and that the resultant lawlessness has driven a great many people to the roads south towards King's Landing, seeking shelter from the continued violence and chaos rampant courtesy of three different sources - The Mountain, the First Men, and the Brotherhood.
In short, I believe that HBO took on a monumental task in filming what a great many people had assessed as impossible to adequately portray on film, and while they do an admirable job, there are going to be times that they fall short of the mark. Also, I highly recommend the books. The wikis can't do them justice. In my opinion, what Tolkien did for fantasy through language, Martin has built upon through sociology, history, and politics.