VFR clearances are not issued to pilots when the weather shows less than 5km vis or the cloud ceiling is less than 1500ft,
From a controllers point of view, in VFR we pass traffic info and you pilots separate yourselves. Under a SVFR clearance we would provide the separation between SVFR traffic and other SVFR traffic or IFR traffic,
From a flying point of view, i don't believe you need any extra qualifications to be able to accept a SVFR clearance, but you'd need to check.
hope that helps, if you want more advice i suggest arranging a visit to your local ATC unit, most are always happy to have visitors and they will be able to explain clearly to you the types of service and clearances they offer.