It's pretty tricky... On our original trip, my GF and I (at the time, she didn't have HKID) tried to open an account at HSBC and they basically told us to take a hike. We went to Hang Seng, and they were more accommodating, but required a 'co-signer' of sorts. We had her Dad sign for us.
You might be able to do the same, having your fiancee sign for you.
A note about ATM: I noticed the same thing. My regular bank (Royal Bank of Canada) charges $5 CAD per international ATM withdrawal. Well HSBC Canada has an account that allows unlimited international ATM withdrawals. We signed up for that account, and are going to use that as our main bank from now on. Should save quite a bit of money.
Direct deposits to your bank in HK will be expensive, as will wire transfers. I am going to do most of our Canada > HK banking just pulling cash from the ATM. I think there is a daily withdrawal limit however, but since it's free it doesn't really matter.
EDIT:
This is the account at HSBC UK that has free international ATM withdrawals. You might want to switch or add that account for now.