I love how the issue has degenerated into "If you are a non-white minority, is it not racist to make comments that, if said by a white person, would be considered racist?"
First off, you conceded that your comments would be racist if you were not a mexican based on the fact that you specified you were a mexican in order to escape an accusation of racism.
Therefore, unless you make the dumb-ass assumption that only whites can be racist, your comments are indeed racist.
The ability to form intent on the part of a minor is assuming that the minor should be placed in the same catagory as adults. The issue is not forming intent, but understanding that intent and the individual's maturity and development. I suppose we should execute retarded people too. They can form intent as easily as any adult. There is a difference between a 16 year old and a 30 year old. If you say there are none, there are a number of laws that you must take issue with.