When hostile mobs don't attack you in creative mode, you turn in mob repellers. Lost zombies in my world because they kept going too far from my radius. Plus, it's annoying to have to keep spawning mobs all the time.
I had tried that too and it is not functioning. I think you should blame Microsoft for this problem.
Players in creative mode do not take damage, if that is a bug, the player in creative mode is taking damage.
This is not a bug. Mobs are supposed to have the same behavior regardless of what game mode the player is in.
This is not a bug. You have to experiment with world difficulty, and you have to practice fighting the Ender Dragon before opening your world to others allowing cheats. If you do not have knowledge on how to defeat the Ender Dragon attacking you, you would likely die and have to leave your world to disconnect other players.
This is not a bug. In creative mode, you have to test out how fun your project is, or other players may shortly leave your world.
If there are two blocks with same names, it would be confusing. For example, if a string ID of a cake in block form is minecraft:cake_block and a cake in item form is minecraft:cake, it would be very confusing, because they are very much the same.
Achievements will be removed in 1.12. Because of the removal of features, the game crashes when you switch to a newer version.
Could it be added back? It was a nice song.
Actually, it is better that cheats and bonus chest can be enabled no matter what game mode the player choses for his or her world, because some players can get upset if they want to but cannot enable any of them while they want to play in hardcore game mode.