No parallel unit I know of will act as a surge suppressor, how could it? Unless the spike was diverted to the parallel unit, but I don't see how the spike would know "where to go" unless it followed the path of least resistance. That would be one smart surge suppressor! Perhaps others more knowledgeable will chime in. Same line of thought for your 2nd question. If you include specific pieces of gear by name/model, you might get a better response. A generic discussion may not get the answers you seek. Just my .02...
