Using Digital Signatures in LiveCylce Designer/Acrobat Reader

Hello,
 
I have some questions to make about using digital signatures in LiveCyle Designer.
 
Here are my questions. Thank you for your help.
 
1 - Why is a user always asked to save a copy of the form after digital sign it (acrobat reader)? Well, I understand that this can be a secure measure so that the user can proove at any time how the form was during signing time. However, if we don´t need/want this kind of functionality, can we avoid the "save as" message? (having forms saved at the users disks can be unsecure).
 
2 - My forms have scripts that change the layout of the form depending on who is opening it (for instance, if the user is from the financial department or form any other department).
At the same time, each kind of user needs to digital sign the form.
 
So for instance, a user at the financial department opens a form and see specific text in some text filds or he can even see specific input fields (some can be hidden).
 
After he digital sign the document another user from another department will open the form, but while opening the form, the scripts in the form will change some text in the text fileds and hide (or not) some sections or some input fields.
 
Despite the form is being programtically changed, this user need to see the digital signature from the first user, and the signature needs to be valid. He will then place his own digital signature on the document.
 
I know Adobe as the LiveCycle Designer wokflow for doing this, however my solution can´t be dependent of a specific technology. Plus, I think that while using livecycle workflow, these different views of the forms would be accomplish with rules that would create different files. However, I would like to accomplish this kind of functionalitty using only one file.
 
Is this possible?
 
Thank you