We used Pro/Plastic advisor (licenced from Moldflow) in earlier versions of Pro/Engineer. There were some problems when Moldflow was acquired by Autodesk. PTC maintenance updates of advisor stopped in about 2007, so we stopped paying maintenance on that module. This meant that we could not use advisor when we moved to Creo Elements Pro. We have since bought an equivalent standalone licence of Autodesk Moldflow Advisor, as this provided the latest features of the Adviser software such as the ability to export analysis results that could be viewed in the free Moldflow communicator and access to more comprehensive material database.
I’m not sure about PTC's current Plastic Adviser offering but when we were using it we didn't need a Pro/Mold licence to run it.
You could use advisor to analyse part filling on existing parts modelled in Pro/E without remodelling. It was very easy to use. When you opened Advisor from Pro/E, it automatically created an STL file of the active part which was then opened in a separate Advisor window. All you needed to do then was to select 1 or more feed points and a material. You could then use the default mould settings or change them if required then press go.
As far as I am aware the module was intended as a basic analysis tool for use by part designers, allowing prediction of sink, short shots, weld lines and air traps etc. It only worked at part level and could not accurately model runner systems and warp of parts.
If you need to analyse the runner systems & warp you needed more advanced software like Moldflow Insight which was aimed at Mould makers.
Hope this helps.