You did not mention the level of the game and is this CivIII or PTW? For a non religous civ, I would prefer to go to Republic and never switch again. Now you can fight some fairly long wars, as long as you do not start them. If you start them, then you need to end them sooner.
One way to start a war is to planet a spy. Another would be to sent units into their land (if you do not have RoP). You could make demands or lopsided trades to get them mad.
I am not fond of making RoP or MPP. I will use alliances instead as they expire and do not force you to jump into other wars.