Electronic verification code for efiled income tax return

Hi,

1.  Would like to know if I can log in to https://incometaxindia.gov.in income tax website and partially fill in the ITR-2 and leave it in draft or on incometax website and when I long on next continue from the same and complete it.  Does Income Tax Website website allow for completing partialy ITR-2 forms and then continuuing at a later stage.

2.  After efiling returns, what is this Electronic Verification Code fthat I need to complete the Income Tax Return and how to go about it.

3.  How do I get the Acknowledgement form ITR V and at what step above do I get it, procedure for getting it.

4. Do I need to send the Adownloaded acknowledgement ITR V to Income Tax Department, Bengaluru with copies of documents to support Deduction under Chapter-VI-A and what other documents needs to be sent.

Thanks in advance