@phunkbot : Exactly... The quicksave/quickload is your best friend when using agents and particularly merchants and assassins (spies are so much easier, wonder why...)

Most of all, I use them to remove the Ai generals and bodyguards, but rather than leaving them idle any diplomat, cardinal, princess or captain can capture their attention...

If nobody's worth it around those parts, there is certinaly a city where a little spark in the right place (just so...) will make a big great bonfire...

So as a conclusion, I'll say that spies are much too good (even newly created spies generally have a 93-100 % chance of success) and other agents much too bad (you rarely get over the 45-50 %)