This is a good idea to help users to send and Bitcoin transactions correctly, in my opinion the easy thing to do is to provide confirmation several times, for example email, sms and so on, if you can provide an option can be canceled when there has been a confirmation that we set then it better.
Not any option for canceling after transaction or sending bitcoin this most important before sending keep recheck how use correct address or not, usually I always save wallet receiving bitcoin or when sending another coin on my exchange market account. Not have to copy address again because have on saving wallet for sending coin. I think this good way always use correct address when sending your bitcoin, but have other perfect way when sending bitcoin better use QR code and looks most effective without worry with wrong address.