Inherent evil?

[HerenIstarion]

Eru proving just how hot-to-trot he is by letting Melkor try to mess things up but in the end it all working out just as Eru had intended

well, knowing somebody is doing something is not making him/her do it, isn't it so? Eru, as a creator, is out of time he created. Melkor, as well as the Valar (not ainur in general, but those who entered Arda) are in it, so bound to move, so to say, along it's line. Any deed thay are goig to make in the future is unknown to themselves before they commit it (though they saw the vision and sang the song, their knowledge of things to come is limited). But Eru, being outside it, sees it as a whole, therefore knows what Melkor (or any of His creatures)has done, is doing or is going to do at any particular moment. In truth, there are no "did", "does", "will do" for him at all.That does not banish the free will conception as well - cause for one moving along time line, the matter of choice is always present - turn this way or that, be good or evil, kill Gollum or jump over it, and so on.