Commerce

Job opportunities abroad are available if you hv a global awareness and competency so try to gain those skills and participate in projects wherever you study or whatever degree you take.
Coming to courses, read this to choose.
http://www.hotcoursesabroad.com/india/find-your-course/how-to-choose-the-right-course/study-abroad-after-12th-commerce/

yes if your age is 18 u can give exam for clerk

Yes, you could do BCom and BBA and others and then go for MBA even if you don't have maths in 11-12. But is dropping the subject possible?

As a commerce student you have many options after your +2
Depends upon your interests.
If you think you understand commerce well you can go for professional courses like CA or CS or CFA.
And if you have a good English and mathematics background you can Pursue MBA.
Besides all this their are many more options available.
But all is on your interest.

Yes you can but it is recommended that you join a coaching institute. If you don't want to join atleast subscribe online mock tests that will give you a fair idea about your strength weaknesses, pattern and competition level.

PCM is must for engineering.

Dear nainesh
For teaching career you have 2 way like
B.ed or you can take net exam for colleges level lecture ship and even you can start PhD programme for teaching career.
All the best

HelloAn indifference curve is a graph showing combination of two goods that give the consumer equal satisfaction and utility. Each point on an indifference curve indicates that a consumer is indifferent between the two and all points give him the same utility.
visit this link for more information
http://wikieducator.org/Indifference_Curve_Analysis
hope this helps you.
thanks
Best of luck