B.Com

Don't do it through correspondence, do it in distance mode. It will be a value addition. It is definitely beneficial.

Marks scored in graduation are considered to apply for B.Ed, not Master's degree. 50% for general category and 45% for reserved category. So, you are not eligible for B.Ed.

Yes, you can pursue MBA directly after qualify GMAT.

Yes, you can get admission.

There is no additional course which needs to be done along with B.Com to pursue MBA. You just need to prepare for MBA entrance exams. As you said, if you want to shine in the field you are dreaming about. You can take up a certificate and short-time distance courses in that and once you complete it, all that will be added to your resume. It will definitely fetch a job easily with a good pay scale.

Dear,
Commercial mathematics is very simple, you shouldn't worry about that. Now, taking into account the CBCS syllabus, mathematics is compulsory.

As per current policy you are eligible to seek admission in 3 years LLB after BCom as there is no age limit for LLB examination this academic year of 2017-20 batch, as the Supreme Court has stayed Bar Council of Indias (BCI) notification fixing age limit for law courses. Age Policy on 2018-21 is yet to be declared.

You can study in Bangalore then in Mysore. It will be a good choice. It's because there are many businesses schools.