English Spl

You written and verbal English should be good. If you can do it, you will have a bright future. You can try to write content for the websites. You can complete your PG and Ph.D and then try to get an overseas job.

There are certain applications which can help you learn English.

The best scope is that you can become a professor after doing this course.

A little training can speed up things. Fortunately, now-a days there are number of online courses which one can pursue in their free time.
You can check the below mentioned link:
https://www.wiziq.com/courses/search.aspx?qry=english.
Good luck.

By speaking, you can learn spoken English. Begin your interaction, right now. With practice, you will do well in a month. Listening practice is equally necessary. You should create a right English speaking environment by exposing yourself to English, you will lose many of your inhibitions.
I would suggest you that you should practice your stresses well with the help of good pronouncing dictionary.

No, there is no added advantage.

Dear Acharya,
Digital marketing is taking place in the marketing scenario, but if you do MBA and then go for digital marketing, it will help you to get a job.
All the best.