Let's first look at your stats:
Your GMAT score is good, but not great. Obviously you are closer to the averages for Davis and Irvine than for the other schools.
Your undergraduate GPA (even at 3.0) is a problem, but I assume you feel that you have explained that away. Schools may cut you some slack there.
Your work experience, while very interesting, is light. You really have only 2 years full-time work so far and the first six months were not managerial. You will be competing with people with 5-6 years or more managerial experience.

The positives:
You graduated from a respected university.
Your work experience is from the Pacific Rim, a priority, especially with the West Coast schools.
You should play up the education aspects of your work experience. That sets you apart from the other economics and international relations applicants.
You don't say whether you are a US or Canadian citizen. The latter could be helpful if the school has fewer Canadian applicants this year.

Your combination of strengths and weaknesses means your essays and recommendations will have to be sparkling in order to catch the imagination of the admissions committee. Be sure to stress those factors that imply that you will bring an unusual perspective to classroom discussions. Schools want diversity of opinion, background and experience, rather than just ethnic or geographic diversity.

You may want to consider working with an admissions consultant who can help you identify and communicate the most compelling aspects of your story.

In all, there are no guarantees, but your chances are better with Davis and Irvine than with UCLA and USC. If you are determined to go to school next year, you should consider adding one or more safety schools, schools for which your stats are representative of, or better than, their average student.

Good luck,