Definitely skip Hearthfire unless you're playing it on 360 (and it sounds like you're playing PC, anyway). I'm only saying that because I've never touched the 360 version, so for all I know it could still be skippable. As for the others:
-The PC version is pretty much redundant unless you're playing unmodded. There are mods available that can accomplish Hearthfire's ends without the idiotic limitations.
-I've played and
reviewed the PS3 version of Hearthfire, and it's got an ass ton of bugs. I mainly downloaded it because I really wanted a place to display all of my specialty weapons and trophies, which turned out to be a horrible idea. Now and then the weapons I worked so hard to earn would randomly disappear for good. Others would be permanently stuck in a display. Even though it gave you the prompt to remove it, you wouldn't be able to. The worst were weapons that didn't remain in their displays. Some would fall onto the floor, others would slowly rise out of their positions, and others would become permanent fixtures of the house. I had one sword that progressively levitated off a shield display until it was sticking through the floor of an upstairs bedroom. It eventually vanished.
I'm not sure if these bugs carry over to the 360 or PC versions, but the PS3 release is definitely glitch-laden crap.
The only thing my milkshake brings to the yard is a subpoena.