Ok - held my tongue for long enough!
Re avoidance of unknown non participating traffic - MATS Part 1 and the Mil JSP552 both state that the controller "shall pass to the pilot the bearing, distance and, if known, level of conflicting non participating traffic, together with advice on action necessary to resolve the confliction" Therefore, if there is no agreement with the VFR pilot, the controller MUST attempt to achieve standard separation (5nms or 3000ft in Class G). This is standard practice for military controllers - are we saying that our civilian colleages choose to ignore this MATS Part 1 definition?
Actually achieving standard separation without negotiating with the multitude of FIS aircraft on frequency can be close to imposible at times. Therefore it is only sensible that some form of WORKABLE agreement is made with FIS aircraft on frequency that may have been identified but not told as such. The procedures to follow in agreeing coordination with a pilot under FIS are clearly and sensibly stated in mil JSP552
Overcontrol of FIS aircraft is a key issue and it sounds like North South has been on the receiving end of this. Of course we have an obligation under FIS to warn of 'aircraft in dangerous proximity' (try to define that exactly - another good topic for discussion!) But we must not turn FIS into RIS and blur the services.
Airspace is a problem - but more importantly, how can a certain Highland 'International' airport justify operating IFR in Class G airspace without search radar?