1. On the return trip back to spamc...spamc dies with a failed sanity check error.
I suspect this is an error related to the user running spamc being different then the user running spamd.
It shouldn't be.. Perhaps it might happen if the user running spamc doesn't exist on the machine spamd runs on, but otherwise you should be OK
I tried running spamd with the --username=root, but the spamd wouldn't start saying that it won't run as a non-exsistant user or as root.
True.. don't force spamd to run as root, as it's a security risk. If you have to force spamd to always run as one user, pick an unprivleged one like "nobody" or create a special "spamd" user.
2. I can't figure out how to get the spamd running on the other machine to read the user pref files located on the machine running spamc.
That's going to be tough, if not impossible to swing. Certainly there's nothing built into SA to support this. Spamd reads the config from the machine spamd runs on and doesn't have any real access to files on the machine running spamc.
Perhaps by doing some kind of network mapping and careful abuse of the $HOME on the spamd machine you could do this, but this strikes me as dangerously fraught with security holes.
