lolz... it shouldn't be this hard, huh?

Can I suggest that you use googled pictures to explain what you have? Here's what I think is going on.
The only way you could have an atomizer that screws on to an eGo-T battery yet still shows larger threads on the outside, is if you have an eGo 510-T atomizer like this:
http://img16.imageshack.us/img16/1702/510tattysideon.jpg
When it comes to the eGo-T, I haven't seen those atomizers too often since the market is dominated by the atomizers described below.
The
regular eGo-T Type-B atomizer looks like this:
http://vaporgeek.com/images/Joye eGo-T atomizer type B_1.jpg
You see it has the same threaded post inside, but the atomizer tube hides it, giving a more polished look on the unit.
Then you have the Type-A atomizer, which is a cone, like this:
http://www.centraltrade.eu/images/eGo-T-atomize.JPG
It also covers the actual threaded post inside, just like the Type-B, so the unit looks more complete.
The Type-A and Type-B atomizers do not use the outside threads you point out. I thought they were used by the battery charger, but it seems not... so I'm afraid I have no clue what those threads are used for.