Brother William,
In doing my research for this very text - Romans 16:7, I found some very interesting  information that I believe will be of interest to you, also.
As we both know, Greek is the original language the New Testament was written in. So, I looked at the original language for this specific verse. Here's a breakdown of some key points:

Junia in the original Greek is  Ἰουνιᾶς, ᾶ, ὁ.  Noun, Feminine; Phonetic Spelling: (ee-oo-nee'-as); Definition: Junia, Junias, a Roman Christian. -Strong's Greek Lexicon-
Therefore, your statement "...but more likely its a sobriquet (nickname) for the very common name Junious" is incorrect. Junia was indeed a female, according to this.

 "Kinsman" that Paul wrote to speak of her in the original Greek is συγγενής, ές.  Adjective; Phonetic Spelling: (soong-ghen-ace'); Definition: akin, relative. -Strong's Greek Lexicon-

Your point that women received ministerial licences but were never ordained as elders/never served doesn't make sense to me?