Interesting Epiphany About Eko

Today I just happened upon an article indicating that Adewale had asked to be written off of LOST.  I found that pretty interesting.  I've pretty much decided that The Cost of Living, the episode in which Eko died, is my least favorite of the season, and I've been very cross with the writers about it.  I still am, but maybe this lets them off the hook a little.  Seems to me it would have been better just to let the polar bear finish him off; at least then it wouldn't have impugned his character.  And what was the point, anyway, of having John rescue him only to turn around and kill him off?  Seems like it was just so John could assuage his guilt for getting Eko into that mess, but it sure didn't do much good.
At the end of the second season, Eko's faith was strengthened to its highest point yet while John's was shattered.  Eko was right.  So why should he suddenly undergo such a major crisis?  I guess he has a right to feel put-upon, having just been nearly blown to bits and eaten by a bear, but I just don't understand why they had to make him renounce all of his spiritual progress.  It was a crummy thing to do.  And then to just brush the character aside, sort of sweeping his death under the table so the other folks wouldn't panic...  I don't know.  The whole thing just seemed very off to me.  The more I think about it, the more it annoys me. 
For a while I was thinking he was only introduced to act as a foil for John and then disposed of once the implosion of the hatch rendered him unnecessary.  But this article would suggest they had more in mind for him.  What was it?  And why did the Smoke Monster decide to zero in on Eko?  Was it checking up on him because they'd faced off before, looking to see if he was still worthy and deciding he wasn't?  Eko's death was the worst of them all, I think, because as my friend Beth pointed out - and her reflections may have colored how I read the episode once I got caught up to this episode and realized it was the one she'd referenced, though she didn't mention any names, and I'm sure I would have been disgusted with the way the episode played out anyway - this death put his soul in jeopardy.  None of the others did that.  Well, no, I suppose Nikki's, and maybe Paolo's, did, but they never made much of a positive impression.  But we cared deeply about Eko and wanted him to embrace this holy man persona he'd once adopted merely as a disguise.  This was a character who mattered.  He deserved better.