With many of VD's "awkward" sentences, there is actually a quite reasonable way to read/interpret them so that they don't sound awkward. However, I think the point here VD is that the player might often need to read a sentence twice in order to hear things with the right intonation.
There's an important difference between written dialogue and speech. With speech, you automatically hear the sentence said in the correct way. With written dialogue you have to pick an interpretation as you read. In general, the longer the sentence, the more possible interpretations there will be - and the higher the chance you will get it wrong the first time.
If you want things to flow smoothly, I think it makes sense to prefer shorter sentences most of the time.
For instance, take the following:
...a corrupt guard here, a few smugglers there; those who sell stolen goods and those who buy stolen goods, and many, many others.
Reading it though fairly straight leaves me thinking that it should be:
... those who sell stolen goods, those who buy them, and many, many others.
However, with the right pauses and emphasis, what you have originally is perfectly acceptable. The trouble is that I don't read it with the right emphasis the first time through. I can only make it sound convincing by reading it through more than once, making a conscious effort to get it sounding right.
When I do get it sounding right, it's better than my "corrected" version - since it needs to be said in a very individual way to come off properly. In a way this is a good thing, since I can't just read it through without knowing how it is said - I really have to hear that character say it. However, it does mean I need to read it twice.
A lot of players probably won't read it twice, but will instead continue with a "that's a bit odd" thought or two.
On one other particular point, I think Azarkon is right on this:
Like a parasite, it sucks gold, the lifeblood of trade, getting fatter on it and corrupting people.
The "and corrupting people" just seems a bit out of place style wise. I think the following is a little better, but doesn't exactly preserve the meaning, so might be no good:
Like a parasite, it sucks gold, the lifeblood of trade, getting fatter on it {and/,} corrupting all it touches.
EDIT:
Azarkon said:
Not sure if this is a typo or not, but it should be "don't," as "won't" implies that you've rejected Loremaster Feng before, and that doesn't seem the case since he's giving you the quest for the first time.
Whoa. Deja vu.