Yeah, the belching and Morty's annoying fucking voice are there... to annoy you.
It really does manage to set the tone for the kind of "fuck you" comedy that the entire show is. It's just hostile. They're -trying- to make you angry, or at least on edge. It's like Bob's Burgers does the exact same thing too, but they're more subtle about it. Rick just dangles his taint right in your face and laughs while farting.
Which is one of the GREAT things about Rick and Morty. But I concur.. the first 2 eps.. you just have to power through. It's worth it.