I started out similar to the OP and started out wanting Google only. The answer is simple: Resistance is futile. Just embrace it. Bing is a little different, sometimes better, sometimes worse, than Google, but overall it's adequate.
As for the barcode scanner, all smart phones these days have that functionality. What's your complaint? If you don't like it, don't use it. I use it frequently though. For instance if I read about an app that I want to try on WPCentral on my computer, there's invariable a barcode that I can scan with my phone that takes me right to the app. I'm also using MyFitnessPal to try to lose some weight, and it scans barcodes on food packaging to make entry of those items easier; just scan, confirm number of servings, and you're good to go.
I wish there was a way to disable/reassign the Bing button, but there isn't, so there ya go. Just get used to it, or get a different phone.