Accounting

CA should be avoided if you have problem in accounts
But even CS has company accounts subject in intermediate level so
you need to pass it however

Yes you can. bcom F and A is offered by many reputed institutions in india. however since you did not have maths your options for admission will be limited and you may find the course difficult too. you can try private colleges if you are very keen on finance. places like DU will accept you only for bcom regular not honors or finance

Australia. it is alao the logical choice containing the opportunities there

I doubt if you can study accounts without mathematics. Business studies require some amount of mathematics. You need to check the syllabus carefully beforehand. You can check BBM programs or short term.diploma courses in business management.

You only have answered your own question. As a science student you took non technical course like BBA and successfully completed it. So even in MBA, you can take finance subject and complete it.
Believe in yourself !!
All the best !!