Visa application process

Hey guys, I’ve got some questions regarding visa application process. Please take some time to suggest some answers for following questions.Any suggestion would be very helpful.

  1. Do we really have to show bank balance transactions of last six months? Does it matter if I showed bank balance transactions of last five or even four months? 2.If I were to be partially funded by my cousin currently residing in US, do I need to prove my relationship with him in relationship certificate or Affidavit of sponsorship written and signed by my cousin would be enough? 3.Please provide me a list of the types of documentation that visa interviewer considers essential.

Thanks.