Switching Tier 4 to Tier 1 dependent visa

Hi
I am working in the UK on Tier 4 doctoral extension scheme visa and would like to switch to my wife's Tier 1 exceptional talent visa as a dependent. I am going to apply within the UK. Has anyone gone through this route?

My specific questions are :
1. Marriage certificate: does it need to be apostilled in the home country?

2. Other documents section in the online application, it asks for proof of living together such as C tax, utility bills etc. (Though it is not under mandatory documents). This is tricky as I am in the UK on Tier 4 since 2014 and my wife came more recently in Feb. We are at present living in different cities so do not have such documents.

3. Does my wife also need to submit her passport/BRP during the appointment?

Any advice on my application would be much appreciated.