but during your post, I thought of your daughter and what she would be feeling. You have a very legitimate cause to be angry, hurt, sad, emotional...all that. And at the same time, your daughter has the same right to her emotions which will be along those very same lines. She will also have a very healthy dose of confusion and worry. It will be impossible for her to "choose" between the two of you.

Does the high road suck? Yes, because you would like nothing more than to also vent all of your feelings. To cut Amy out of your existance as far as possible is what the emotional side of you wants. It would be hugely appropriate for her to not have her cake and eat it too (your financial support without the relationship work or consideration).

For what its worth, let me say this. The high road may suck for you to take, but I think that it is what is needed for your daughter. By being civil to your daughter's mother, there isn't the chance that your daughter will see you "being mean" to her mother. This is something to avoid, because you do not want to put your daughter into the internal conflict of choosing between the two of you. In other words, I think that if you place the "taking the high road" mentality as being for your daughter, then it will be easier for you to deal with.

At least, that's how I would put it if I was in your situation.
~Jeordam