B.A Economics

Yes, you can do it. But before that check eligibility criteria where you apply because like dse, JNU has the eligibility criteria for Maths. But other institutions don't have it.

Duration is three years for fees and for cutoff, check official website.

Usually it's not possible you have to study three years. But if you want to change college for your third year than it's depend on that college where you are willing to apply usually for change of college allowed.

Harvard, London school of economics, stanford Universities are the best for economics and have much scope and bright future.

It's totally entrance based exam. You should check their official website for it and cut off too.

Yes but usually most of universities and colleges have eligibility criteria you have to check eligibility criteria for every college or University.

No, MA is not necessary. You can apply for B.Ed after B.A economics but for assnt. professor, MA is necessary.

It is not necessary in most of the universities but in higher studies like M.A. Maths not compulsory but it's better if you have background because in M.A. you'll need Maths for application of economics so it'll help you otherwise you are gonna to struggle a lot without Maths in M.A.

B.Sc. Economics is best option where you can do much better as B.A. You'll learn practical problems more than theory with Maths. But B.A. Economics with Maths stats and eco best combo for B.A. Also much better but package are different. Research both and find your area of interest where you want to go theory or not.

Yes you do it CA professional course allows it but usually students won't take another course because it's better or u can say more helpful and beneficial with commerce stream.