参考翻译：

备受争议的提议主要包括，联合国将成为美国自由的威胁，开国元老们可能并不想教堂和国家完全分离等教学内容。

结构分析：

这句话的主语和谓语是：The proposals include...that the United Nations could和that the Founding Fathers都是teaching的同位语。may not have intended是对过去发生的事情表示不确定的猜测。

3.We have pushed relentlessly for BP to do what is necessary to contain what is leaking, to deal with both the environmental and the economic impacts of what, as the president said today, is unquestionably a disaster.

参考翻译：

我们已经严厉地向BP施压，要求他们采取必要措施控制漏油，应对环境和经济方面的双重影响。就像奥巴马总统说的，这无疑是一场巨大的灾难。

语法学习：

as the president said today是插入语。

大体而言,插入语可以分为以下几类:

1). 用简短的句子结构作插入语。这类短语有:I think, I hope, I guess, I believe, I suppose, I wonder, I tell you, I say, I'm afraid, I'm sure, you see, you know, as you know, that is, that is to say, what's more等等,它们可以置于句中或句尾。如:

I suggest you choose someone who you think is kind and friendly.

This diet, I think, will do good to your health.

It won't be raining long, I hope.