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200 Sound files??? How long is your project? After Effects is not an editing app. It is especially not an audio editing app. Adding more than a sentence or two to a comp is almost always a bad idea and a pretty inefficient workflow.
As far as sequencing layers all you have to do is select them in the Project Panel in the order you want them in the comp and drag them in, or select layers in the order you want them sequenced in the timeline (Shift + Ctrl/Cmnd + click will select any layer in any order) and then use the keyframe assistant to sequence the layers. It takes just a couple of seconds.