Regarding German Work Permit while on Schengen Visa

Hello,

I am an Indian resident, and have a Schengen Visa valid for 3 months. I need to apply for a long term work visa for Germany.
I am already in Germany on Schengen Visa. I have following questions:

1. Can I apply for Work permit from within Germany?
2. Since the answer for q1 is mostly NO, can I go back to India, apply for work visa, and then travel back to Germany while my Schengen visa is still valid, to continue my ongoing business meetings? Since it takes 6-8 weeks for work permit to be granted, I will be able to minimize the time lost waiting for the same.
3. Can I authorize someone to apply for the work permit on my behalf in India, and after it is done processing, on granting of the work permit, I can visit the consulate in India for stamping?

Any help or guidance will be greatly appreciated.

Thanks...
get2abhijit

hi you did not mention what kind of german visa you have it .is it visit or work permit?