Teacher

Yes, you are eligible to become the lecturer of political science subject.

You need to complete M.Com and qualify NET exam.

Both qualifications and experiences are needed to become a principal in government and private schools. After the completion of both the courses, join a school.

There are n number of government B.Ed colleges in each district. As you are working, you can do your B.Ed in the deputation period. To get 2 years deputation period, you have to take permission from the authority. You can also pursue B.Ed through distance from IGNOU.

D.El.Ed is compulsory for untrained teachers who are teaching in government schools, but if you have completed B.Ed, then D.El.Ed is not required.

Do B.Ed and start preparing for TET, this will lead you to a teaching job.

Yes, it is possible but you need to clear an entrance exam.

For attending the TGT exam, you need to be a minimum graduate in any discipline from a recognized university.
You need to have scored at least 50% of marks in the graduation level. For PGT exam, the candidates should have a PG degree with around 50% of marks from recognized university or college. For attending both the exams, you need to have a B.Ed.