Too much of a good thing

Yan asks:

Could you help me with the meaning of "there is too much of it" as in the following passage marked in capital letters? What's the exact Chinese for it? Can you give me other examples?

The original goes like this: A mountain 2,000 feet high would be a horrible monster here, as wrong as a plain 400 miles long, a river as broad as the Mississippi. In America the whole scale is too big, except for aviators THERE IS ALWAYS TOO MUCH OF EVERYTHING. There you find yourself in a region that is merely part of one colossal plain. You can spend a long, hard day in the Rockies simply traveling up or down one valley, you can wander across prairie country that has the desolating immensity of the ocean. Everything is too big; THERE IS TOO MUCH OF IT.

And here I have another question: does the word "as" play a contrast role in the following sentence? The original: The beauty of our country - or at least all of it south of the Highlands - is hard to define AS it is easy to enjoy. Hope I didn't bother you too much.

My comments:

Never mind the bother, Yan. Just fire away with your questions and let me handle the rest at my discretion.

That is to say, I may choose to answer your letter at length or in brief, or not at all, but the discretion must be mine and mine alone. Otherwise, I may begin to wonder if I have given you too much freedom (to write in), and freedom, you see, can be too much of a good thing.

Obviously I may not have the time to answer every question from every reader, but I give y'all the freedom to write in and post a question any way - and with it the possibility of being frustrated in case any letter went unanswered or were not answered in a satisfactory fashion, either in terms of detail, length or timeliness. You see, I understand the consequences both ways.

We must therefore trust each other to be doing their best without being excessively demanding. Otherwise, like I said, I may wonder whether this freedom (I give you readers to write in) isn't too much of a good thing.

Too much of a good thing is a phrase dating from the 15th Century, according to the Oxford Dictionary of Quotations. Shakespeare used it in As You Like It: "Why then, can one desire too much of a good thing?"

This is the answer for your first question. When there's too much of something, there's an excess of it. And when there's an excess of it (too much sugar, for example, in coffee), it often becomes less desirable than it normally is.

Thyroid hormone, for instance, is the secretion by the thyroid gland which regulates the metabolism - the rate at which our body burns fuel. Normal amount of the hormone is good and necessary. But when there's too much of it, the metabolism becomes too fast. And that may lead to hyperthyroidism, a condition under which people may lose weight despite eating more. So therefore, thyroid hormone can be too much of a good thing - it may do you more harm than good.

In Chinese idiom, we find a similar expression in Guo You Bu Ji

As for your second question, Yan, you should consult the dictionary - look up "as" as a conjunction. I may add that the way you framed the question suggests that you've more or less got it right.