How might a provider pull together better, easier ways to explain,
instruct a. using less of what might be perceived as jargon and b.
using less what might be perceived as arcane references, how might a
provider more easily explain, more easily instruct end users with these
questions?... end users with areas of expertise not directly applicable
to...

1.
What can you do with the spamassassin headers?... spamassassin headers
have appeared in the headers at the top of messages in emacs rmail.

2.
And how do you do the things you can do with the spamassassin
headers?...

Around the web the instructive material about spamassassin didn't
appear to meet the needs of end users, given the usual explanations
deferring the matter to another department, the provider, the isp,
someone else not me and so on.

Or what example or examples are there by way of individual spamassassin
hints, tips, pointers, features?...

Unrelated, but here's an example of providing hints, tips, points,
features
http://www.apple.com/pro/tips/