It really depends on the type of care work and position you will be holding. Sometimes you do have to register with the Scottish Social Care Council. It is a fairly recent thing, it looks like in the near future all care workers will need to be registered with them.
They have lists of qualifications that are currently necessary for registration, depending on each position and who you work with.
http://www.sssc.uk.com/All+about+Registr…
http://www.sssc.uk.com/All+about+Registr…
Examples of minimum qualifications needed for registration for a support workers in residential care would be a S/NVQ level 2 in Social Care, but in day services they dont need to register, only managers do. It seems like if are working towards a qualification you will also be considered for registration.
If you have experience, and that would definitely help you get a job, but employers are increasingly looking for qualifications even if there is no legal obligation yet.
Apply for jobs and see how you get on.
Best of luck
UPDATE-
Get in touch with the social services council, it depends on who you work with. That is the answer, no one will be able to tell you any more than that!
Why don't you practice as a nurse? Do they not recognise your qualification? There must be a way around that. look here- its about working holidays, but I think it shows that you can register with the NHS.
http://www.nhsprofessionals.nhs.uk/Overs…
If you have trouble finding work, you should get your name on the list of the Nurse Bank. They provide nurses and health care workers for relief work, and the pay is not bad. A friend of mine used to work for them in Glasgow when she was a student nurse.