Regarding the name "Valentia" there's a curious story to be told. Pliny the Elder's Natural History (Book III) says about the city of Rome that
"it is a sacrilege to pronounce its second name except in the mysteries of ritual ceremonies. Having been kept rigorously hidden with the best and healthiest observance, Valerius Soranus made it public, and was soon punished. It is not inadequate to mention in this respect the case of an ancient cult instituted mainly because of this secret. The goddess Angerona, who is offered sacrifices on the twelfth day before the January calends, has her statue with the mouth tied up and sealed."
The editors of the Gredos translation add a note, to this effect:
"The 'second name of Rome' apparently was, according to Servius, 'Valentia' a supposed Latin translation (an inverted translation) of the translation into Greek of 'Rome' ('Rhomé', meaning 'strength'). Soranus, a former Marian, took refuge in Sicily, fleeing Sulla, and was executed there by the praetor, Pompeius." (Plinio El Viejo, Historia Natural: Libros II-IV, ed. and trans. Ana Mª Moure Casas, Antonio Fontán, and Ignacio García Arribas [Biblioteca Básica Gredos] Madrid: Gredos, 2001, p. 197).
The second name of Rome may have been a secret, but the Romans did not seem to think that the law of silence should apply to the naming of Roman colonies as well.
(A commentary to Language Continuity: "Toponymic Notes (1): Valentia").