Yes, that makes sense as far as proper acquisition timing for the AI. The one thing I don't understand is the AO sample clock and triggering. You wrote:
"Configure AO to be triggered by the rising edge of the external pulse while using the falling edge as a sample clock."
I don't understand this. What is the difference between setting the "active edge" of the sample clock and the "edge" of the Start Digital Edge trigger, if they use the same clock source? It seems redundant to me. If I set the sample clock of the AO to the falling edge of my 2ms hardware signal, it will generate a sample and send it out of the AO channel. What, then, does setting the trigger to the rising edge of the 2ms signal do? Won't this override the falling active edge I set on the sample clock, and instead generate an AO sample on the rising edge?
I think you're right that the AO trigger I recommended is redundant. It doesn't really accomplish anything. (Note that it doesn't hurt either. It wouldn't "override" the sample clock settings. Triggers and sample clocks are very distinct for NI DAQ devices.)