We might just as well be doing that as lying awake here.

参考译文：醒着躺在这儿还不如出去做那件事。

其结构(1)为：主语+might just as well do sth(A) as doing sth(B)

主语与其做B件事倒不如做A件事.

I might as well die as marry him.

我与其嫁给他，倒不如去死算了。

其结构(2)为：主语+may just as well do sth 意思：主语不妨做某事

You may just as well tell me the truth.

你不妨把真相告诉我吧。

We may just as well buy a new frying pan.

我们不妨买一只新煎锅。

If you don't like to swim, you may just as well stay at home.

如果你不想游泳,你也可以呆在家里。

这句可以不可以变为:

We might just be doing that as well as lying awake here.

谢谢回答！

回答如下：

主语+might as well do sth as do sth属于固定搭配，不可以改变其顺序.

(1) might as well 还是…的好 最好，倒不如，不妨；莫如；何妨

You might as well tell her the truth.
你倒不如把真相告诉她。

You might as well throw your money into the sea as lend it to him.
你借他钱不如把钱扔到海里去。

I might as well die as marry him.
我与其嫁给他，倒不如去死算了。

You might as well not know a thing at all as know it only a little.
只知道一点点，不如完全不晓得。

In that case, I might as well bring them back with me.
那样的话，我还不如拿回去。

He decided that he might as well have it out with them.
他决定还是和他们把问题谈清楚的好。

Business is terrible I might as well pack up.
生意很不好做--我还是关门算了。

They are after you, you might as well clear out.
他们正追你，你还是离开的好。

She is looking forward as much to his return as he himself(is looking forward省略了) to  her.（OK)

as much as 表示程度 与....一样

在英语语言中，为了避免重复，一般都需要省略.写出来是帮助你更好理解。