A, there's currently no rules stating that there mustn't be spam on the forums.
B, rule #3 says,
The staff members are always correct.
Since Shane and Kim are staff members, that means they're correct here that they have the right to spam and get away with it (as they're "staff").
Also, rule #2 does say,
Don't be evil.
Trying to deliberately invoke annoyance by "spamming" like what you've threatened to do probably counts as "evil" in this definition