Most states have a law for mudflaps. Even your old state of Michigan has a law for mudflaps. But there are stipulations when applying this law. On most privately owned trucks that are stock hieght. Usually they are not required to have mudflaps. Most mudflap laws pertain more to commercial or farm vehicles. Because they do not the fenders to prevent the tires from throwing things or kicking up debris from the road.
I know your truck and it is low enough I would not worry about putting mudflaps on it. Heck look at my truck I don't run mudflaps.
As for the diesel smoke law, that is more of an emission thing. Usually you don't see it enforced all that much in farm states. But that is not saying it won't be enforced. But again your truck is not that bad so I would not worry about it.