Give us the option in Safari, for the "Reader" button to be on the left. It's that way in iOS 7, and my mind wants to look for it automatically there when I use my Mac.
I don't see what the problem is, it's on the left by default in 10.8.4 / Safari 6.0.5
And dan1eln1el5en is correct, Apple employees/engineers *might* dig through forums like this but they really aren't supposed to. http://www.apple.com/feedback/safari.html is a much more direct line to them. Don't expect one request, or even 50 requests, to make changes though. If Apple starts to see a high percentage of requests for same/similar features then it will likely become a reality. If they only see 3-4% of requests for a particular feature then it won't be an area of focus.
you can change and move around and change every such item by going to View->customize (uncertain last wording as I don't use an english version of os x - but definitely under "View")