While I have certainly heard of the urban legends about Chinese parents threatening to disown their children if they married someone who was non-Chinese, I have yet to see or hear any such threats given to my friends or family members, many of whom are dating or married partners of other ethnicities and most of them being first-generation immigrants.
As for racist attitude among "Whites", I would agree it's definitely not overt and generally not serious. However, it wasn't that long ago during the SARS epidemic that such comments were made:
"And you people live like rats and eat like pigs and spread dirty, dirty, deadly disease around the world" - hate phone-call to Chinese Canadian National Council
I have also had personal experience of racist comments thrown at us, usually by older White people. A few years ago I was at a bank with my parents, we were in line and my dad went to get a deposit slip and fill it in. An old white lady behind us then complained, "Stupid Chinese." My mom turned around and said something to the effect that she was being rude and racist etc, and for reasons I cannot remember now the old lady left the bank after a while. A middle-aged white lady in front of us then assured us, "It's ok, she's old."
This certainly wasn't a common experience, but it exists nonetheless.