Frame your browser as the mobile version of Safari and you get those pages. Its all in how the sites are seeing your browser - they do this for their mobile users only. Probably because of screen space more than anything.
Number two is just plain wrong as the cloning era proved true, you should never try to directly partner with a competitor in the fashion that you propose unless you are forced to. It never works out well. Look at Apple's problems with Samsung for example - largely they exist due to the fact that Apple relies on their IP to some degree. The last thing you want to do is create more reliance.
You simply do not license out and sell your own property like that - you end up...
Why? Apple allready has a filter for valid devices. If they believe a device is invalid they can either blacklist it or do some other identification. My guess is that they will blacklist and use legal tactics to make sure this doesn't last.
I can understand some of their frustration, while it is possible to downgrade the iOS software, none of the methods are endorsed by Apple and none of them are provided from them either. Some people might be apprehensive about doing something outside of what Apple provides thinking that it would certainly void warranties or the like.
Simply put, since Apple doesn't provide a methodology anywhere, most people would be convinced that it wasn't possible.