Accounting & Commerce

Yes, you can pursue B.Sc in psychology if you are comfortable with its subjects. It will be good if you look for some commerce oriented degree course like B.Com/BBA/BA which are in-line with your 11-12th courses.

You can choose between M.Com and MBA after completing B.Com. You can also obtain professional qualifications such as CA, CFA, etc. You can also do certifications such as NSE, IIBA, etc. to enhance your employability. You can also do skill based courses. If you had mathematics as a subject in class 1

You do require any special degree to become a book keeper. But, if you really want to be a book keeper then some institutes provide certification courses for the same.

The scope of CS is good in terms of career in corporate industry.

Yes, you can pursue graduation while you are pursuing CA and you can also pursue CA in commerce field as it would be helpful in your career.

Yes you're eligible for FMS delhi.
Finance, Marketing, Organizational Behavior & Human Resource Management (OB & HR), Production and Operations Management, Entrepreneurship, Information Technology Management, Services Management are offered.

If you are interested in management then go for BBA and if you want to be a tax expert then go for CPT. It depends on your interest.

You can learn about trading and equity research from NSE which offers various courses in trading and shares, capital markets, forex management and derivative, etc.