Hey guys,
I go into a meltdown.
Maybe this is your problem. Not sure how old you are but as you age and become a bit more mature normal wear and tear such as you describe becomes less of an issue. (not making a judgement on you personally, simply stating priorities change as you age) You should of taken your bumper off more often and cleaned the dust out OR put edge protection on your phone like those available at
http://www.theluckylabs.com I know people want to keep their i's perfect forever but that's just not very realistic when most "abuse" their phones by their daily actions.
To answer your question yes, marks on the edge of the i4's is perfectly normal. I would think if you're as iOCD as you say you would of taken the bumper off on a regular basis and cleaned your phone. Maybe you're progressing and didn't even realize it.
I will also add ANY case/bumper will do the same. It's not the case, it's the dust/dirt that gets in there that causes the issue. It gets in there and acts like fine grit sand paper with the very small movements of the case against the phone. Only way to stop this from happening is to remove the case and clean house.
There have numerous threads regarding the bumper scratching the stainless steel band on the 4/4s. But yeah that bumper does more harm than good on the band of those devices.
This statement is total bunk. The bumper is a great way to protect your phone while still being able to actually "see" the phone. Great (edge) drop protection, minimal footprint and easily removed. You simply have to be proactive in taking care of your phone.