Ok, so i will make a detailed thread shortly, but it looks like its not quite so automated.
I choose a film on Radarr, add that to my library, then ask it to search, it finds the right nzb/torrent and sends it to the correct client. Client then does it job, finishes off and unpacks. At this stage Radarr can see its finished and reports "No files found are eligible for import in *dir*". Which would have me thinking something has renamed something somewhere, but the dir it gives has files, and if I manually import (but not the button on the activity section, the one on the wanted tab), I can add it to my library and Radarr moves and renames fine.
What can I give you that would make diagnosing easiest? Logs, settings, or something else?
//Fixed it myself, its not clear that the data folder has to be set EXACTLY the same all around, i had it pointed to a completed folder thinking that would also work as it was were things were completed.