Class 12-Commerce

No, to be a pilot you need to obtain commercial pilot license from a DGCA approved institute and to do a CPL, you need to clear your 12th with physics, chemistry and biology with minimum 50 percent.

You can appear for SSC exam after completing class 12th, but these are clerical level jobs.

In 12th you are going to have subjects like:
Accounts
Micro and macro-economic
Organization of commerce (OC)
Secretarial practice (SP)
or
Maths
English
and one optional language (Hindi Sanskrit)

You can go for following options:
B.Com MBA
B.Com MCA
BBA MBA
BBM MBA
B.Com LLB
BA LLB
Advertising
Hotel management

The main difference between CA CS studies is that in CS, you are going to learn more about company law and in CA, you are going to learn more about accounting and taxation.

After completing your M.Com you should take the NET exam and you can become a professor. You need to pursue Ph.D in any one subject.

Sorry but after 12th with commerce you can't take admission in medical. For that you must do 11th and 12th with science.

You have many options like:
B.Com
BBA
BCA
BBM
BA
Hotel management
Mass communicationAdvertisingAnimation
LLB
You also have options like:
CA CS CMA with B.Com
Short term diploma like
Diploma in taxation
Diploma in foreign trade
Diploma in import and export
Other than this you can learn foreign language like French.