Indian citizen applying for a work visa from UK

Hi, I'm Winston. I'm a nurse from India. I came to UK(2013) as a student, did my B.Sc in nursing and got married to an Indian citizen who was here already here since 2010. She was on sponsorship visa when we got married and later on to do her Masters she transferred her Tier 2 to Tier 4 visa by keeping me as a dependent. Now, I'm in the process for getting registered as a nurse in UK.

so my query is, If I'm applying for work visa from my employer do I need to go back to India then come back or can I proceed my paper works from UK itself?
If my wife applies as my dependent, does she need to go back to India or can she apply from UK itself?

Hope someone can help me to clear off my doubts.

Regards
Winston