Question Regarding Canadian Marrying an American in the US

This is kind of a very specific set of circumstances that I was hoping people here may be able to shed a little light on.

I am engaged to an American and living in Canada where we have just become common law. We would like to get married in Hawaii in August, but I am concerned that there may be border crossing issues to and from the US.

In particular, my concern arises from a US border agent possibly thinking I won't leave the US once we are married. Would having documentation proving our return flights be enough to solve any issues?

Second, when returning to Canada after the wedding, would there be any issues with her entering Canada using her student visa, considering the change in our relationship status? I assume that it wouldn't be a problem given that she has a multiple entry visa under which she originally entered Canada and that we are already common law.

Does anyone have any thoughts on either of these issues?

Thanks,
Chad