My FSX is installed in J:\Flight Simulator X, and my Active Sky Next for FSX is installed in J:\ASNext_FSX. I/m pretty sure you can install Active Sky Next for FSX, or Active Sky Next for P3D, anywhere you like. I have Active Sky Next for P3D installed in C:\Program Files (x86)\HiFi\ASNext_P3D (it's default location). Both work fine in their respective flight simulator programs.
Sorry, but I don't have Edit Voice Pack, so I can't help you with that.