Dumb Diplomacy: I think I may have discovered the solution.

[Didz]

I've spotted a couple of gliches with the 'Friend-o-Meter' which I've mentioned in passing, but its not too bad overall. As far a sabotage is converned I don't think it affects your reputation with anyone other than the faction occupying the target at the time. At least I've not noticed anyone else upset about me blowing up Rotterdam apart from the Dutch and the French who happened to have ships in the harbour at the time.

Incidently, I've just spotted that you get a -10 Territorial Expansion penalty every time you take a province in the same theatre as another faction. Thats something to watch-out for if you want to stay friends.
[Hmm! thats weird. Actually its not just with factions that own territory in the same theatre. I just took Texas and got a -10 on Russia and Prussia even though they are not in America, and yet I got no penalty on the Ottoman Empire, Muhgal Empire or Maratha Confederacy. So, how's that work then?]