I hope ur telling about CEH (Certified Ethical Hacker).
Answers for ur Questions!
1. The course is good, many advanced courses are also available, but this is the base.
2. yes, lot of companies have a ethical hacking team. U can get a job if u re worth paying.
3. I don't know much about CCNA, but I think U can do CEH without studying CCNA.
4. this will be according to the company, if u re in an MNC u may get around 6L (CTC) or even more.