Please note I have just posted a response to your questions at NBS as well.

The evidence for the scenario I mentioned in my earlier post is almost entirely based on exprapolation. It is the evidence of the beads themselves that suggest this likely movement.

You mention "glassblowers." It is very typical and common to speak of glassworkers as being "glassblowers," because in modern times very many do blown work, and we are used to thinking in this conventional term. However, glassblowing was invented about 2,000 years ago—which means that a lot of glass was produced before any blowing ever took place. Further, in the area of beadmaking, blowing is of minor importance when compared to the other techniques that were exploited. Many more beads are wound, drawn, or molded, than are blown.

Consequently, at 400 BCE, it was not "glassblowers" that may have imigrated to China. Better to say "glassmakers" and "glassworkers."

The imigration I have have described is suggested by the evidence of the beads. At around 500 to 400 BCE, typical Mediterranean glass beads were exported to China, and are now recovered archaeologically. (That the Chinese wanted to receive glass beads from Persia—by which could be taken the Eastern Mediterranean lands—is historically recorded.) Unfortunately, because they were recovered in China, they are sometimes misidentified as being "Chinese," rather than as import beads. However, they are quite recognizable. It was soon after this time that locally-made glass beads were manufactured in China. These Chinese beads have several aspects in common with Mediterranean glass beads, in terms of technique and style. It is easy to propose that one group was inspired by the other. What is different, primarily, is that the glass composition is unique to China, and noticeably different from Mediterranean formulas. The element barium is the most stand-out difference. The first paper to deal with these issues in relation to beadmaking is a significan article by Horace Beck and Claude Seligman, I believe titled "Notes on Sundry Asiatic Beads." This is a must-read for anyone pursuing these questions.

The manufacture of glass, beginning with sand, ash, and other constituents, is a complicated process. The working of glass, once the glass is made, is likewise a very difficult and demanding occupation. One does not fall into it without considerable training, and a lot of invested time. So, when glass is artistically exploited in an area where such work was not pursued earlier, the easiest explanation is that glassmaking and glassworking were introduced from elsewhere.

It could be suggested that the Chinese sent some artisans to "Persia" to learn glassmaking, and they returned and developed the industries that shortly later made Warring States beads. There are few reasons to exclude this idea, except that it is well known that the secrets of glassmaking were carefully guarded from the knowledge of outsiders for thousands of years. Even now, the tradition of secrecy is largely continued today. American studio artists of the past twenty years are among the first people creating a movement that is based on sharing information. Europeans, for instance, still remain very cautious about their work. Well, I digress. It is easier to suppose that people who were conversant with glassmaking and glassworking imigrated to China to take up manufacturing glass products there. Any suggestion that glass might have been "independently developed" by the Chinese, based on their knowledge of ceramics (a typical suggestion), is not based on a sound knowledge of glass requisites. What I propose is the most parsimonious solution to the question.

Also, please remember "Phoenician" is a short-cut term for a larger situation. To be sure, many glass beads that were circulating at this time were made in Phoenician or Phoenician-controled lands (what is now Lebanon, and certain Phoenician colonies or outposts in other regions). However, many of these beads were made in Egypt, and probably additional Eastern Mediterranean or island places. Nevertheless, it was the Phoenicians, historically, that had the entreprenurial initiative to take their beads (and glass products) as well as those of the Egyptians and what ever else they could buy or trade for, and to take them all around the Mediterranean lands to trade to others. So, in a broad sense, these beads can be characterized as being "Phoenician beads." This does not mean they were all made at Phocea or Canaan. And, it is not intended that actual Phoenicians went to China. The imigrating glassmakers may have been Egyptians or Persians, for all anyone knows. The point is the the inspiring beads were of the Mediterranean style and tradition..., and that (clearly) Warring States beads evolved out of this manufacture.

If you are not familiar with the book The Glassmakers, by Samuel Karinsky, I recommend it. While there are many passages with which I disagree, I think Sam has gone out on a limb to express ideas that hold water and have some merit. I would just not be inclined to be as exclusive as he is in his admonitions and theories. Sam is not astute about beadmaking, though he does mention beads occassionally (though not as often as warranted, due to their real importance in the spread of glass technology).

So, to answer your question, I do not believe any sites have been discovered where glassworking or glassmaking were pursued in early China—whether operated by Chinese craftsmen or foreigners.

There are many sources of information about the Phoenicians. I highly recommend The Phoenicians—a catalogue (as big as a phone book) of a huge exhibit that was held in Venice about thirteen years ago. I expect it may be difficult to find, but represents the current knowledge of the subject. I didn't see this show, but a friend brought me the catalogue.

By "faces" do you mean classical Phoenician face pendants? No single work reproduces a truly comprehensive collection of these works. There is one article that analyses them thoroughly, but it's illustrated by drawings and graphs, for the most part. (Sorry, the title and author are not at my grasp at the moment.) Among the best places to see these things is through the catalogues of auction houses, and also from museums that have specimens in their collections. (I think first of the Corning Museum, the British Museum, etc.)