Did 謠's phonetic component (䍃) semantically shift it away from 言?
Did the phonetic component 䍃 spawn, or have anything to do with, the semantic narrowing from 言 to 謠?

&quot;䍃&quot; is a common 声旁, 谣 is a pictophonetic character (形声字), its   pronunciation is from 䍃, 摇, 遥, 鹞 are pictophonetic characters from 䍃 too.

If not, what beget 謠's songful (#1, 2 below) and defamatory (#3) meanings that are more specific than 言?

What's 歌谣? Some words with tunes. What's 谣言? Fabricated words without facts. What's 言? Words. 言 is the meaningful part of pictophonetic character 谣.

For example, consider 謠言. Couldn't 謠言 have been originally compounded as 言謠?

&quot;谣&quot; is the &quot;adjective&quot; of &quot;言&quot;. What type of words&quot;言&quot;? Uncertain or suspicious words. If it's 言谣, &quot;言&quot; and &quot;谣&quot; should be parallel.

Actually, I can't understand your exactly question because in fact, your question can be clearer.