Why is the Python documentation terrible in this respect? Python comes with a language reference[1], that has most of the components you ask for (one of the components is in a document that's
called something other than the language reference, but that's because it's the stdlib, not the language itself... it's certainly the same style of document, not a tutorial!):
1. Syntax (sections 5, 6, 7 and I guess also 9 if you want the full grammar)
2. Whitespace (section 2.1)
3. Operation priority (section 5.15 has it explicitly, the rest of the sections also clarify)
4. All functions, types, classes... both globals and stdlib modules are documented in http://docs.python.org/library/index.html#library-index
5. All parameters? Documentation should already have these.
6. Callback parameters: I can't think of any callbacks in the stdlib offhand, but the ones that do exist are methods you implement, and all the ones I can think of are documented
7. Default values and their meanings are pretty much always documented
8. I don't know what flag values are, but if they're just parameters they fall under (5)
9. Return values and exceptions should always be documented
10. There are plenty of cases where some input parameters causing undefined behavior is documented; some maybe not (for example I don't think urlparse.urlsplit documents what happens when you give it a scheme it doesn't know about), but MOSTLY it's documented.
[1] http://docs.python.org/reference/