Placement of object with adverbial phrase I am wondering about the placement of "这件事" in these two sentences:

1) 这件事你做得越快越好。
2) 你做得越快越好这件事。

In English: "The faster you do this, the better."

#2 makes more sense to me since the object comes after the verb, but I assume that both are ok. Which feels more natural to a native Mandarin speaker?

What if we remove the adverb phrase?

3) 这件事你做。
4) 你做这件事。

or 事情你做。vs 你做事情。

Would 你做这件事" and "你做事情" be more natural? 

Does the adverb phrase cause the object to need to be placed differently, or am I missing some other rule?
1) is natural. 2) sound unnatural without context. In certain contexts, 2) can be used.

1) is an example of a topic-prominent sentence.

"这件事" is the topic. Everything that follows the topic describes it. i.e. "你做得越快越好". When there is a topic, you can usually translate it literally to English in the form of "As for [topic], [things following the topic]". So here, 这件事你做得越快越好。 can be translated as "As for this thing, the faster you do it, the better".

Other examples of topic-prominent sentences include


  我头疼。
  
  lit. As for me, head hurts. (This is different from 我的头疼 where 我的头 is the subject and 疼 is the verb. In 我头疼, 头 is technically the subject)
  
  笔借我一下。
  
  lit. As for the pen, lend it to me.


I will probably use 2) where I want to emphasize that you should really do it ASAP. That's why I tell you to do it fast first, then the thing that you need to do, just to be clear.


  Would "你做这件事" and "你做事情" be more natural?


你做这件事 sounds like I am telling you to do this thing, instead of some other things. 你做事情 sounds unnatural.

3) is another topic prominent sentence, it translates to:


  As for this thing, you do it.


I would say that 3) puts more emphasis on "you" while 4) puts more emphasis on "this thing".