Yeah Baratheons seem to be very small in number. Aside from Robert's bastards that is. But in the show, a lot of them were killed. Now that Gendry knows who he is, Team Baratheon gained one more member. But that may not spell good news for Gendry given Melisandre's whole deal....
We do have Shireen Baratheon. Stannis' adorable little girl. OMG SHES SO CUTE IM GONNA DIE! AHHHH! If Davos gets to share more screen time with her, ill be thrilled. GoT should be the Davos and Shireen Show! Agh! <333 (sorry...had to gush)

Team Stark...it is odd isnt it? That its only really Ned's nuclear family left. Well, there was Uncle Benjen (Ned's brother) but he sorta vanished off the face of Planetos. Karstarks are actually linked to the Starks. Almost like a cadet branch House. (at least they began that way.) They are distantly related to the Starks.

WHO DID IT! WHO SPOILED THAT!


This is an OUTRAGE! YOU CANT JUST SPOIL SOMETHING LIKE THAT AND GET AWAY WITH IT! THATS JUST BULL♥♥♥♥! RAGH! Thats one of the, if not THE, biggest things that happens in the whole series! Omfg....

If that had been spoiled for me, id rage and rage. Ive tried VERY hard not to spoil that, but still dropping hints to people to get ready for ♥♥♥♥ going down.

This is actually going to be answered, but Jon pretty much spells it out to Ygritte (and vice versa). Jon tells Ygritte about how they cant win. Ygritte in the previous episode told him that she knows that in his heart, hes still a "crow" (Member of the Night's Watch) They are both right.
And you mean Craster.

Ok. The deal is, A while back before the series began, the Iron Islands tried to rebel against Robert Baratheon. (the big fatso king from season 1) Ned Stark was among the guys who squashed that rebellion into the dust. As a way of telling Theon's father, Balon Greyjoy, to shut the ♥♥♥♥ up and deal with it, Ned took Theon as a hostage. But Ned being Ned, treated Theon more as a ward or fostering. Theon had brothers but they died during that rebellion. So that left Theon and Asha (oh right, shes called Yara in the show) as the heirs. Since Theon was the last male Greyjoy heir, this was a big blow to Balon and having Theon in Stark hands made Balon behave himself.

When Theon goes back to the Iron Islands to ask his father for a fleet for Robb's forces, Balon and Asha Yara shame him pretty bad and keep going on about how hes not a real Ironborn and ♥♥♥♥. This makes Theon have quite the identity crisis and this is why he double crosses Robb. To prove hes a real Ironborn. Pay the Iron Price and ♥♥♥♥. So when Theon gets his orders from his daddy, he thinks "oh ill take Winterfell because its completely undefended! ♥♥♥♥ yes!" And he succeeds as you saw. But yeah, his own guys realize they are ♥♥♥♥ed (for reasons that the show will reveal very soon) and bag Theon and get the ♥♥♥♥ out of there.

Also Theon's Captor is actually a spoiler. But a hint: The Ironborn didnt torch Winterfell. You arent really missing anything here because it just hasnt been revealed yet. Episode 9 will make everything very clear...( D: )

The old guy yer talking about is Rickard Karstark. One of Robb's bannermen. (you know, the one that was beheaded by Robb for killing those squire hostages?)

Tywin didnt really own Harrenhal, he was occupying it because the guys who DID own it yield it up to Tywin for his war effort. Since then, its been handed to guys who would never step foot there. Like Janos Slynt who ended up being dragged off to the Night's Watch in season 2 because Tyrion was all "lol no get out." And then it was offered to Littlefinger. (its technically still Littlefinger's btw.)
But really, Harrenhal was occupied by a couple of really nasty guys in Tywin's army. Gregor Clegane (the Mountain) and Ser Amory Lorch. (the latter seems to be entirely absent from the show...) Thats why it was in the state it was in when Arya was there.

In the show, Tywin left Harrenhal and Roose Bolton took it over and occupied it with Northern forces. That guy, Locke, is actually a composite character of a dude in the books who led a nasty mercenary group called the Brave Companions who rode with the Mountain and ♥♥♥♥ed ♥♥♥♥ up. That mercenary group seems to not really been included in the show. (aww.) So the show rolled the leader of that group (named Vargo Hoat) into this character named Locke.

Right now, in the show, Roose still occupies Harrenhal. But hes leaving, if you recall, to attend the Tully wedding at the Twins (House Frey).