plenty of weaker ones with notably strong Talents actually - Edit 1
Before modification by darius_sedai at 10/12/2015 06:26:36 PM
The major character reply is a bit of a cop out. I agree we have seen weak channelers with Talents, but not many. Berowin, Sumeko, Androl.
Aside from those you list here are some that come to mind
Healing
Samistu level 20
Corele level 18
Damer Flinn
Chesmal level 18
Suana level 22
Aligning the Matrix
Neald
Weather
pretty much every Windfinder, the circle for the Bowl of the Winds had women as low as level 18 (Azzara was the weakest at level 1
Reading Residues
at least 6 very weak Aes Sedai including
Akkarin level 34
Therva level 34
Shana Level 35
Nacelle level 36
Nisain level 37 (was stated as the best)
Reiko level 38
Traveling
Ahsmanaille level 22
Yukiri level 14
Cuendillar (not sure if this is Talent or simply Earth affinity)
Kairen level 18
Leane level 14/36
several weaker Aes Sedai as well as novices