A) F1 is by its nature a team sport, even though sometimes we wish it wasn't, and this rule "clarification" makes it less of a team sport.
B) This is a rule which leaves a lot up to the interpretation of the stewards (what is a coded message?) which makes it a poor one and is sure to cause drama at some point, but I'm sure the FIA totally didn't think of that.
C) I don't think it'll change as much as people think (hope?). Despite all of the jokes (haha Chilton is so bad right?) these are still some of the best drivers in the world, they know how the cars work, they know how their tyres work, and they know how much fuel they have. Speaking of fuel...
D) The FIA does not want teams to tell their drivers how much fuel saving is needed, but teams only have 100kg of fuel for the races, which, if memory serves me correctly, is not enough to finish most if not all of the races. Are teams allowed to tell the drivers how much fuel is left? This is not explicitly mentioned in the list of permitted messages. Does this fall under "Information on level of fuel saving needed"? Because drivers have no way of telling how much fuel they have left unless the team tells them.
E) STOP CHANGING THE RULES IN THE MIDDLE OF THE SEASON FFS
A very poorly thought out rule "clariication" in my opinion, only pushed through now to make the fans happy. I'm all for less radio messages and giving more power to the drivers but I wish they would have waited until the end of the season.