M.A

Yes, it will be good for you to pursue MA English from DU for your future prospective.
All the best.

You can prepare for the CSIR net.

You have opted for B.Com in the UG, then opt for M.Com. Otherwise, you should pursue MBA. Try to finish the course which you have started.

Yes, you can. After completing graduation in any subject, you become eligible for MA English. But, in most of the university you have to appear for entrance test. In some universities, they give extra points to the students who study English at graduation level.

It depends on what specialisation you choose in MA. MA in economics is very much in trend. This sector is hiring so you can apply to one of these colleges for MA in economics:
Indian Statistical Institute - Kolkata / Delhi.
Delhi School of Economics, Delhi.
Indira Gandhi Institute of Development Research, Mumbai.
Madras School of Economics, Madras.
Gokhale Institute of Politics and Economics, Pune.
UPES, Dehradun.

Delhi School of Economics Is the only post-graduation college under University of Delhi for economics, commerce and geography.

There is no specific requirement for a PG, however you may opt for NET / sET and go for coaching. Apart from that, government including high courts have various opening such as counsellor, livelihood officer etc. You can pursue your career in that.