It is not in the least confusing to those who have kept abreast of JAR/FCL and NPPL developments. I would expect an Examiner to have taken the time to have done so.
1. You can find the SSEA definitions in ANO Schedule 8. Together with the legal requirements to include specific additional complex variances, but not to exceed the SSEA weight limit or act as PIC if the total PoB exceeds 4 including the pilot.
2. Flight at night or in IMC is not permitted unless the licence holder has a JAA Class 1 or JAA Class 2 medical certificate. A medical declaration is insufficient.
3. SSEA is a national category, not a 'JAR' category.
4. The recent medical exemption allows those pilots, who would otherwise need to apply for NPPL issue in order to continue flying, to do so on an exemption to their JAR-FCL (or UK) Pilot Licence until it falls due for re-issue. That exemption limits them to the same privileges as a NPPL holder.
It really isn't rocket science.