Forget this idea, you cannot protect PDF by hiding parts of the interface. Consider what would happen if someone just uninstalled Reader - they will be asked to save the PDF instead.
What you need is DRM. This doesn't stop files being saved, copied, shared or emails, but controls who can open them.
If the acrobat is uninstalled, it won't download but will say 'missing plugin'.
Then the uninstall didn't work properly. Anyway that's just one of many ways to save the PDF instead of viewing it.
What you need is DRM.