After three episodes, I'm getting a better idea of what Shameless is supposed to be about. The characters aren't bad people and aren't malicious in intent, but they sometimes have to stoop to a certain level of wrongness to survive. Forcing (or tricking) the old woman to become Aunt Ginger was wrong, but then they wouldn't have money for gas. Likewise, Steve constantly bothering Fiona is a little creepy and wrong, but she does come to him in the end, and he can provide money for bills.
Ultimately, the writers aren't telling us whether we're supposed to like the characters. Everyone lives with a degree of moral ambiguity, some more than others, and taking the sum of their actions, the audience will always have different reactions. Personally, the only character that is really unlikable is Frank, who is wholly irresponsible.
Score: 8.7/10