First off, speed, no hard feelings, we're just arguing over the internet, no reason to get offensive
I do however get the feeling this conversation is not really going anywhere. But see, the burden of proof is on you and you don't seem to point at any ideas or emotions it explores. It seems like, in fact, you are not even talking about Lolita specifically, except for the allegorical remark (I explained why I think it is not very accurate).
Can a real character be put on paper? Of course not. People, even stupid, materialistic, people, are much more complex than any character. All writers fail at the impossible, literature fails by definition. But the greats are great because they tell us about deep emotions that we didn't even know exist, because they understand, at least partly, how the human mind works, because they have new ideas, because their books can change the way you look at your life, give you inspiration. That's what makes for great literature. And it doesn't have to be serious. Pynchon describing a sexual act with images of a stupid movie on TV and teenage hippies playing guitars is funny as hell, but at the same time shows us its meaninglessness and mocks the fact we've come to think of everything in symbols.
I don't understand your remark about characters. Do you mean in the sense that they are just parallels of existing characters? Or that they don't have a life of their own? IMO, Dostoevsky's characters are not fully believable since they're all motivated by ideals (even cruel ones), but they are brilliant... They have moods, development, even subconsciousness, a way of thinking and talking that reflects all these things. I actually think Dostoevsky is a better psychologist than he is a writer. It's hard to believe he has not murdered old ladies himself! But there are many others, and even if they're not fully realized there is always something humane about them, either to learn from or to avoid, and it's cruel to compare them to the robotic caricature that is Humbert who is supposed to be a parody to begin with.