Re: ORLY?
[...] though I do worry about how easy it would be to extract my signature from the document for use elsewhere.
It's rather too easy, unfortunately, even if you use the standard "Encrypt PDF" settings and restrict copying, because opening the resulting PDF in Chrome and resaving it strips the encryption (it was only ever an honour system between different implementations of the PDF standard). You can then select an object (e.g. the jpeg of your signature) and copy it out.
Even if your attacker doesn't feel like going to those lengths, anything they can see can be screengrabbed.