How do I get

I am a copywriter publishing a PDF to be posted on the internet for downloading by end-users. The PDF is designed to open in full screen view – that is, without tool or menu bars visible. This means it would be helpful for me to embed additional functionality onto each page of the PDF for technophobes who do not know or want to know keyboard shortcuts.
In doing so, I have found that when adding the dynamic zoom tool function via Acrobat’s Advance Editing > Forms > Button Tool, the dynamic zoom tool only works in some versions of Acrobat Reader and not others.
I suspect this is because the dynamic zoom tool is accessed from different locations in different versions of Reader. Therefore, the instruction that I embed in to the button tool that relies on a menu-tree command (‘find the tool in this location via the menu’) cannot be executed.
Fortunately, it appears that there is a javascript name available for the dynamic zoom tool that I can use instead of a menu-tree command. But unfortunately, it appears that the script name is different for different versions of Adobe Reader...
Not to be outdone, we have managed to write a small piece of javascript that, when assigned to the PDF using the button tool, identifies which version of Reader the recipient is using and activates the correct script name.
So far so good.
However, it now appears that version 8 of Adobe Reader has a higher level of security built in, so that javascript is security restricted and isn’t allowed to run.
This of course means that the button I’ve included in the PDF to bring up the dynamic zoom tool doesn’t work at all for end-users using Adobe Reader v8.
Getting the users to adjust their security permissions in the preferences is problematic and less than ideal. I really want the PDF to work ‘out of the box’ so to speak, without the users having to perform somersaults to get every element of the PDF to function fully as designed.
And seeing as the end-users are part of a public organisation and will not necessarily have the authority to update their software from v8 to v9 themselves, I am a little stuck.
So what’s my query? I’ve got more than one:
• Is there a more detailed script I can assign using the button tool to get the dynamic zoom tool to work as outlined above in v8?
• Can I raise the security level of the dynamic zoom tool from within the PDF (that is, so that the dynamic zoom tool activates automatically and without end-user intervention, e.g. without downloading bits of code to place in file directories)?
• If I were to assign a digital ID/certificate to the PDF, would this allow the javascript to run unhindered?
Here's hoping one of you wizened starlets can help me on this one!