...print abilities disabled...
If somebody can view a document on their computer, they can also print it. That proposition is true as a matter of pure logic and does not depend on the details of the technology involved. Here's one argument to convince you that this is true: If you are viewing a document on your monitor, there must be some physical process taking place in the computer that is able to translate the "secure" data on disc into a set of coloured pixels to display on the screen that represent the document. At that point, the data has been revealed, and nothing stops you from swapping out the screen and sending the array of pixels to the printer instead. Your immediate response might be that that only lets you print the first page, not the entire document, but the mechanism of scrolling the document isn't magic -- if you can do it with your mouse, you can also do it with a machine. So it is indeed possible to print the entire document in a fully automated fashion,
if you can view it.
Attempting to prevent somebody from printing a document that they can view on their own computer is an example of pseudo-security rather than actual security. And, as a consequence of the foregoing, the Adobe PDF restrictions on printing do not actually work once the person has unlocked the document; at that point, the person can easily print the document through any number of means. (The easiest way would be to just use a PDF reader that does not enforce the printing restrictions!)
That said, attempting to prevent somebody from
viewing the document by encrypting the data in transmission and at rest is an example of actual security, and the Adobe PDF password mechanism is a good implementation of that, so I still recommend using that mechanism -- just don't expect it to stop people from printing the document once they can view it.