I'll second the vote for touching up paint and not worrying about putting "the first scratch" on it. I've touched up a bike in better shape and it is a great 5-footer (looks good from 5 feet away). You can of course spot the touch-ups close up, but I'm just happy knowing they are protecting the bike from rust. If yours has no rust, touch it up and let the remaining Imron paint continue to protect it.

My 2 cents