Could you translate me one sentence?
 

thanks in advance.

I read it as some really slangy way of saying something (not sure what) about being noisy/annoying and a gay otaku

Not quite. "Game freak", not "gay otaku".

"You're being a pest, game freak!"

"you are fuckin' annoying, Geek!!"
うざい(uzai)＝annoying
ゲーオタ(game otaku)＝geek

Haha. Thanks for the correction. :) The オタ is still from オタク, right?

Right.

When we katakanize "gay", we do so as ゲイ most of the time for some reason.　

right.
ゲーオタ means game otaku.
アニオタ means anime otaku.
鉄オタ　means train otaku.

I would like to know if we can still use "otaku" to mean "you".

You'd sound very, very weird. I lived in Kanagawa and went to university in Tokyo, and never a single time heard お宅 to mean "you."

That's why I ask. I personally haven't heard it. But "you" is the dictionary definition of "otaku".

Yeah, you'll never hear it. You shouldn't expect to use it. I'm almost 100% positive.

Plus, you almost never use any word for "you" in a sentence in Japanese, be it おまえ、あなた、きみ、おたく、etc.