If you're trying to retain the native copy paste edit features with just overlaying a new keyboard, you're not going to be able to do it. You would need to crack open the android sdk etc and build it that way. As mentioned previously you can restrict the zooming with some meta information in the html document.
This is the best I can do for cross platform copy paste, but it will not solve the problem of the keyboard. It uses a method similar to things like CKEditor.
This plugin has native support for paste in only certrain browsers (internet explorer) and displays a dialog prompt for others.
I'll answer about blurring in another post
Please ! You can do the same thing only with copying text to the clipboard ? To me it is very important