"3. Nowhere in the law or our handbooks are we told that names MUST MATCH exactly. We're told that we should be reasonably certain that the person is who they claim to be, and to match their signature to the ID presented. "
I agree with the first part of this statement, but I can't find anywhere where it says that the signature much match the ID presented (although I do believe it should be part of our procedure). I think this is also a matter of interpretation. Signatures do tend to change over time. This can be especially true for people who still have the same signature as when they were very young, or because of a job change or promotion, find themselves signing their names much more frequently than they used to. Also, those electronic devices people have to use at the DMV feel different than a pen on paper and can affect how a signature looks (to say nothing of what they're told by DMV employees! )
Frankly, I don't see that much contradiction. To me, the primary guide is in the very first item listed as a requirement for taking an acknowledgment:
<<§ 1185. Acknowledgments; requisites (a) The acknowledgment of an instrument shall not be taken unless the officer taking it has satisfactory evidence that the person making the acknowledgment is the individual who is described in and who executed the instrument.>>
The only way a person is "described in" the vast majority of documents we are likely to have presented to us is by name. Therefore, it makes sense to me that our job is to match the two, i.e. the person named in the document with the person appearing before us, using "satisfactory evidence". What kind of evidence we are allowed to use is carefully detailed, however the code does not define what is considered "satisfactory". Sometimes the latter requires a judgment call, which is why this subject comes up so often - and is potentially the toughest part of our function as NPs. With this interpretation, the law seems to me to be reasonably consistent - unless I'm forgetting something (entirely possible, especially at this hour!)
I don't think deciding what is "satisfactory" proof of a person's identity is always absolute or clear cut and I believe there can be gray areas. [Remember, CA law just says it's the absence of any information, etc. that would "lead a reasonable person to believe that the person making the acknowledgment is not the individual he or she claims to be".] In what might appear on the surface to be similar circumstances regarding what's on an ID vs. what is written under a signature line in a document, I might handle them differently. For example, if there's an issue and someone gets an attitude right away or tries to use intimidation to resolve the issue, I'm likely out of there - well before the suggestion of CWs is even considered.
But ultimately every notary has to come up with their own guidelines and has to be able to live with the consequences.