I have reached the edge of my own technical capabilities.
I have particles emitting using an instanced sequence of geometries.
Each particle comes into being at the same point in the sequence as every other particle at that moment.
Is there a way to get each particle to run through the sequence independently of the others? Some sort of per particle attribute? I don't know. Please, please, please if anyone knows anything, let me know. I am sooooo confused.
Please forgive my blubbering. It's been a rough period with these terrible evil hideous particles of doom.
Don't panic! The particles are more afraid of you than you are of them. Be assertive and use a firm tone and they will toe the line.
In this case, you need to set a couple of the 'cycle' attributes on the instancer and on the particle shape node itself.
First, turn on cycling by choosing "Sequential" instead of "None" for the "Cycle" attribute on the instancer node. Now choose the "Cycle Step Unit", either frames or seconds. If you do want each instanced particle to cycle through the different objects, set this at a low value, such as 1 frame. If you do not want each instanced particle to cycle through different objects, then this doesn't matter--we'll turn the cycling off in the next step.
Finally, select the particle shape node and open up the "Instancer" tab. Select a value for "CycleStartObject". If you want each particle to select a different object from the list as it is created, choose "particleId". Next, choose a value for "age". By default it will be equal to the particle's actual age, but if as mentioned above you actually don't want your particles to cycle through different objects over time, select some non-changing value instead, such as "particleId" or "mass". This will ensure that each particle instances the same object throughout its lifespan.
Hope that helps! More control can be exerted by using custom attributes, but this method should work for simple cases.