ACS Skill Assessment

Hello All,
I am complete new to this topic.
I am planning to apply for the ACS skill assessment, so in process of preparing the documents.
Already I know that it is very difficult for me to get the Roles and Responsibility document from my employer.

So I am planning to take up an affidavit from my CO-WORKERS.

My questions are,

  1. Is it mandatory to get a document from my employer that they wont provide the Roles and Responsibility letter as per their policy. Looks like for sure I cannot also get this document.

  2. I hope the affidavit from the co-worker can be done in the plain paper and company letter pad is not required, and get notarized from the Notary.

  3. If I miss some documents will the ACS asks for it after a preliminary check or only one chance to upload and send all the documents.