I just got a 95% mortgage. And yes, I paid 10% deposit - 5% when my offer was accepted, the other 5% two weeks later when signing the formal sales and purchase agreement. When the 95% mortgage comes through 5% of it comes back to me. You/your agent might be able to talk the vendor into accepting just 5%, there's no legal requirement to pay 10%, it's purely just that it's the done thing here...
From my (pretty exhaustive (and exhausting!)) talking to banks a month or so ago, none of them were offering above 70% in-house. SCB used to, but not anymore.
The insurance premium if you go through HKMC is added to the tenor of the mortgage so in terms of monthly repayments the extra amount is tiny...for me that was preferable to waiting years to have saved another several hundred thousand to reduce the MIP by a couple of thousand. Also, if it's your first purchase with the MIP then you get a discount. Just to give you an idea - I've bought a little place for $1.76m and the HKMC MIP is $60,000 which really isn't that much in the grand scheme of things.
Hope that helps...