Then why doesn't my Argent Dawn rep account for nothing?

Sorry, but you have no proof on your theory that "the player is already well known". The Lich King doesn't say, "okay you already beat Black Temple, so I know you are powerful". And even if you did, he would be ignorant, since the player would have only conquered BT as apart of an army (raid) rather as one person. No, mmorpgs don't work like this, and Blizzard knows this and hence doesn't assume the player has overpowered certain powerful forces (I mean, not even 10% have beaten Kil'Jaeden in Sunwell). Again, your theory is wrong.

And we really don't know what the Wrathgate poison is, you have no proof that is was anything, for all we know the Red Dragonflight only did this to end the lives of the armies rather and not let them suffer the poison's slow effects. TBH, my thoughts, the Red Dragonflight was only there to make it look like the ending of LOTR (to make it look epic). Even the beginning of the quest could have just been a click of the item on the ground. There is no evidence that your OPINION is truth, so please, stop making rubbish up and saying it is fact. All that I said was based on the facts that were already there.