This is a problem with this version. My theory for this is: in previous versions "6 city Attila" would declare war on "2 city Isabella", but not realize that she has a DP with my 7 cities and 3 CS allies on the same continent. Now Attila is smart enough not to do this, but there is also much less war since it is rare for 1 civ to be more powerful than multiple civs with a DP. I'm not sure what the solution to this would be except to make it so civs are more likely to use joint wars and factor that into their decision making.
I haven't seen this at all, but if you are having a problem with this you can use the mod on Steam called Caravans Build Roads and I guarantee the cities will get connected.
I've had zero problems with crashes, and thus no reason to revert.
I'm not sure how large of a map you are playing on, but I don't have these problems at all.