b) Enroute to Exeter, you are still in cloud and wish to transit say Solent zone, when you call them up although not on an IFR Flight plan do you state condition as IFR while requesting a zone transit?
The abbreviated flight plan required for controlled airspace transit is simply the set of details you pass to Solent over the radio. If you say you are IFR, then you are "on an IFR Flight Plan". However, don't expect the details to be passed on down the line.