As I know you can create an audio reaction animation with 3 effects only :
This might help you as I guess , If I missed your point then clarifide it to me.
You can create keyframes from Audio.
First go to animation->keyframe assistant->create keyframes from audio. These Keyframe values can be used now on every effect you want by using expressions.
temp = thisComp.layer("Audioamplitude").effect("Linker Kanal")("Schieberegler");
the first example uses the audiopeak-value directly (be careful I uses AE in german, I don't know if copy&paste works with other languages), the second one uses the linear-effect to remap your values to a value between 0 and 100. This is usefull when using it for transparency. The four values 0,30,0,100 can changed by you.
0 = smallest audiopeak Value
30 = highest audiopeak Value
0 = smallest output
100 = highest output