You do get more notices as you get more espionage experience - But I agree that you don't get enough. It is tiresome to have to check the Foriegn Relations screen every turn to see if a war is in progress. I don't like to trade all the time, and end up forgetting to check for long stretches of the game.
A few games ago the Drath surrendered ---- and I never even knew they were fighting anyone. Ended up opening up the back door to my empire.