If I was one of those people who's good at writing meta, I'd write about how Clark Kent hasn't really grown up at all when it comes to relationships.
For one thing, it's obvious that his vision of who Lana is hasn't progressed beyond his ten year old ideal.
He hasn't grown beyond that at all. In his mind, Lana is perfect and he doesn't see that she isn't at all like what he thinks. He isn't really in love with her at all. He's in love with an ideal that never was. After he got to know her in real life, Clark couldn't allow himself to believe that how he envisioned Lana wasn't real. He still believes she is that perfect fairy princes that Lana confessed so long along to hating.
He puts her up on a pedestal and worships this vision.
In Labyrinth there were so many lines that even if they were spoken in a vision rang true. He said he wished she was real, and he does. Deep down, Clark knows the Lana he loves does not even exist in the real world, but he clings to that idea. This could be because he's emotionally stunted and hasn't really outgrown his childhood.
There's no way I believe that Clark thinks he's not meant to be a hero. There is no way I believe that Clark is supposed to be with Lana for the rest of his life. I'd work that into the essay somehow, because I think this is very significant. Deep down, Clark knows that this is what Lana would want. She's a demanding girl. She has constantly demanded his secrets and he has constantly refused to give them up.
So many of the ways Lana has behaved tell us that she is not Clark's idea girl at all. I do believe that she wouldn't accept his differences. Everything we have been shown about her says she wouldn't be okay with his alien status. Not to mention the hate she holds for the meteor "freaks."
Someplace deep inside Clark knows this instinctively. He knows that unlike Chloe, who embraced Clark's differences wholeheartedly, Lana would not be so accepting.
This inability for Clark to move on holds not only him back but Lana as well.
There's so much more, but it's early and I can't remember them. Maybe others would like to add to this. If you have insight, please feel free to comment.