It is a possible theory among others. When Verduci was killed it was reported that there were two Ndrangheta clans that were having a fall out. It was alleged that one of them had close ties with the Cun-trera/Caruana clan.
That would be the Aquino-Coluccio clan.
Yes.
There is also more information of their ties/alliance mentioned in the book Business or Blood page 117.