AnFI
I have no idea what your experience is/was. You choose not to share that in your profile. If your point was that twins are more difficult to handle than singles after an engine failure - as many asymmetric light aeroplanes can be for the untrained - then I might agree with you. However, that's not what you are saying.
For my part, I have suffered a real engine failure (not precautionary shutdown!) on police ops, and in the hover, at night over one of the largest UK cities it is possible to imagine. Had I been flying a single that night, I'm far from certain I would be making this contribution now.
Twin engines are not only mandated (in the UK) for the necessary exemptions to Rule 5. They are the very, very least the public deserve, and it would be idiotic for anyone (particularly with no relevant experience?) to suggest otherwise.
As for the NS point. There are a hundred reasons why an aircraft might end up in the sea. Even jumbo jets carry life rafts! But that doesn't mean we should be carrying passenger in singles across the Atlantic!