Degree

No, you cannot do it before completing 12th with PCB.

BHU is one of the good institutions in India providing degree courses in instrument playing. Take a look at there website.

Yes, as it sounds Bachelor of Science. It means that it is a Bachelor's degree course and you can take IAS exam after this.

Annamalai University offers degrees in distance education mode. If you have done a full-time three-year graduation course B.Sc after HSC, then you are eligible for enrolling in a full-time postgraduate course.
Hope this clears your doubt.

After D.Pharma registration as a Pharmacist by the Pharmacy Council of India (PCI) is granted, so one has the option of opening a medical store which is one of the best options for many. Other opportunities after D.Pharma are in the Pharmaceutical companies where one can find the job of:-
Pharmacist, Production Executive, Chemist, Medical Transcriptionist, Technical Supervisor, Quality Analyst etc. The job of a Medical Representative is also very popular which can be joined after completing a D.Pharma course. There are also jobs in the government sector after D.Pharma.
Regards.

No, they don't offer that.

You can opt some other courses related to your field, like if you are in civil then you cannot enroll for CSE.