Electronic signature

Hello,

I have carefully read the tutorial on the use of electronic signatures Abobe Reader (I have version XI) but I didn't understand how to use it for my use.

In the company I work, I want to use Adobe Reader in order to electronically sign documents. When these documents are written, the writer doesn't have to sign. These documents should be sent to an approver who will sign and approve the document. Once approved, the document must be sent to readers who must also sign the document.
This document is available on our computer network, I wish that all the signatures are on the same document. Is this possible?
Is it necessary to use ECOSIGN? For safety issues I don't want to put the document online.
Does the use of digital ID to send an email?

Thank you in advance for any assistance you can provide.