That is not in dispute and can be said about ANY class. What's NOT in dispute is that tweets are needed to make the class a bit more competitive.
To answer your counterpoints
1: While that is a deep talent of Annihilation, it doesn't the fact that having it low on the tree would give EVERY tree more mobility which they all lack. (player skills/tactics notwithstanding)
2: Agreed Ravage needs help and that was just my opinion on how to do it.
3: Yes, I do know that however, I feel that Ataru needs more as base and other abilities can be tweaked accordingly.
Now these are just my suggestions based on my own experience, playstyle, and what other Marauders have said to me.
Do you have anything to add to the discussion other than "Annihilation should be a special snowflake don't change it" or L2P ?