Medicine-Postgraduate

Do the medical graduate get paid during the Foundation Programme & during the following " Under training Doctor" that lasts for 5-8 years ?
Is the "Under training Doctor" period divided into Masters and PhD stages ? Or is it just equivalent to them ?Is there a PostDoc available stage ?
I am a science degree graduate . Is there a dual available certificate during the "Under training doctor" in science to graduate as a clinician scientist , or do I have to study an independent scientific MSc , PhD and PostDoc , aside my postgraduate medical degree?

FY1 and FY2 are post-qualification from medical school so yes, these years are paid because you are working as a doctor.

Masters degrees and PhDs are not mandatory for UK doctors, but some doctors choose to do these qualifications during specialty training. Each speciality has membership/fellowship exams which you will need to complete if you are on a training programme.

I'm not quite sure what you mean by "under training doctor" but I assume this refers to specialty training? Again, yes this is paid because you are working as a doctor.

There are various academic training programmes and pathways if you are interested in doing research/teaching alongside specialty training but I don't know much about those.