I'm not trying to convince you, because I myself dont know. I'm just saying that I dont see the logic in it at all. It's fine if you think she'll die, but dont expect me to agree with your reason, and that's all I'm saying. The more I read of yours, the more it seems to me that your reasons for Luna being a target are more because of a dislike of her character.
Also, I dont think that those he loves will be anymore protected. He'll certainly <i>want</i> to protect them more, but we've seen a lot of people eat it that he wanted to protect.
I do agree that because of their status as main characters they're less likely to die (though we've seen main characters slaughtered before), Im just saying that the line of logic (closeness to Harry = target) doesnt extend to Luna.
Again, its fine that you think Luna will die, and maybe she does, but the logic doesnt add up.