"Offshore" technically means any bank not in your home country/country of residence. So Switzerland definitely qualifies as "offshore" unless you're well, Swiss.
And Swissquote is awesome. Clunky web interface, but improving. Where it shines is the lack of fees, which I found onerous at HSBC in Jersey and Lloyds TSB on Isle of Man. Either high monthly fees or very high minimum balance requirements to waive them, at the latter two. None at Swissquote and they have an office at DIFC. Nope, I don't work for them. Best to contact them personally and ask about them, as I don't use a fraction of their very comprehensive trading platforms or robo-advisors.
But they'll all be sharing your information with your home country soon enough anyway with the Automatic Exchange of Information changes looming. That's definitely something for professional advice, not free internet advice!