It helps not to have to care a lot about Rep... if you are in world Conquering mode, Rep matters to keep peace while you absorb theothers... I wanted to test this MPP situation, needing to Conquer England next in my program, but they had an MPP with Japan, and she was heighboring, and strong... really did not need two fronts... so, signed an MPP with Japan, and waited for England to attack. You can count on that happening sooner or later, and it did happen on the next turn. She declared war, and I let her make the first attack... Yes, with the MPP only one turn old, Japan declared for me against England.
Funny thing, though, her troops wandered all over my land (without an ROP) but I was not ready to kick them out, and besides she could cross my land to get to English cities. She did take one city -- pop one -- After I signed peace with England, 20+ turns later, I threw them out.
This is a huge world, and I am halfway there in 1810. This is the Kitten of Chaos map, and I have all or the Eurasian continent. It is getting to be too much to keep in my head... Too much land, too many cities, too many units.