Interesting point! I supposed in this case the letter was translated into Common. Maybe the translator added the flourishes to the original telegraphic text you posit?

Another good point! I'm not positive, but I know that ancient Egyptians had fairly elaborate-looking names that they somehow conveyed in hieroglyphics. I think the names often (probably usually) meant something that could be conveyed in ideograms, like "Man with Red Hair" or whatever. In other cases I believe they used the rebus principle (in other word, if English used pictograms, you might write the signs for "air" and "in" to represent the name "Erin").

My understanding is that a lot of pictogram representing abstract principles or actions were also puns on similar-sounding words. To give an example (again pretending English used pictograms), it's hard to draw an intelligible pictogram showing the action of dragging, so the symbol "dragon" might be used instead. "The man is dragging a sack" might be the symbols "man"+"dragon"+"sack", with the context indicating that the second symbol meant "draggin'" rather than "dragon". Or, as another example, you might use the symbol "him" to represent the difficult to picture word "hymn".

All that said, you are certainly correct that pictograms are less flexible and useful than an alphabet, or even a syllabary. I wonder if Jeff envisions the Ixian pictograms doubling as a syllabary, which was sometimes the case?