I'm not sure I'm fully understanding your question, but:

The Iberian script (the semi-syllabary used to represent what we commonly call "Northeastern Iberian Script" (where the vast majority of examples exist) is a combination of adapted Phoenician (or Greek) letters and "local" syllabic symbols. There is no connection to Nordic runes whatsoever, and the similarities are just coincidence: the two are separated by half a millennium in time and a thousand miles in distance. The Phoenicians began arriving in Spain in the middle of the 8th century BCE, especially at Cadiz and the Costa del Sol, and there was some transmission of script/alphabet during that contact among the Celt-Iberians. The Greeks came a century later, particularly in the northeast of the peninsula along the Golfe du Lion to Marseilles. Some believe the script was transmitted earlier, during Mycenaean excursions to the Iberian peninsula, but the evidence is slight for that to say the least. The 7th to 4th century as time of transmission works best on current evidence.

We know very little about Iberian. You are right that the language seems to be rather unique, but so are the other paleohispanic languages (Basque included). Its semi-syllabary is pretty neat, but the morphology is virtually unknown at this point.

As I'm looking around now, I'm seeing a lot of crackpot notions surrounding this topic. Academia.edu is not a trustable place for scholarship, and there is a lot of garbage there. There were not rune-singing Vikings sailing from the Baltic and paying visits to the Iberian Peninsula in the 4th and 3rd centuries BCE. :)

Unfortunately, there is not a lot of bibliography on this topic in English. It is understandably ruled by the Spaniards, and of course the Germans have a presence, as in all academic topics. This one looks interesting: de Hoz Bravo, Javier (2011) Historia lingüística de la Península Ibérica en la Antigüedad II. El mundo ibérico prerromano y la indoeuropeización. Madrid