Rick,
When you install PlanetPress Imaging on a separate machine, the only thing that will change is whether or not PDFs created using the "Image" output connector are generated locally, or on the separate server.
PDF Tools provided by Office/Production such as CreatePDF, using PDFs as a data file, or the Concatenate PDF task, are not affected by this move.
Converting incoming postscript print jobs in PDF format is unafected.
Digital Action will still render PDFs using Workflow's Alambic instances, as long as PlanetPress Imaging is installed on the same subnet mask (192.168.0.X for example).
So really, only the Image output task is affected by this.