Origin of the Epirotes?

[Rosacrux redux]

NONE of them has anything to do with the Illyrians, at elast ethnically and linguistically. The Molossians and Thesprotians are typical northwestern Greek tribes, as the Orestes, the Eordaeans and (sorry, this will be the sole mentioning of them) Makedones. They have clear Greek origins, did not mix much with the "barbarians" (even semi-barbaric Greek tribes, like the Athamanes who also occupied a part of Epirus) spoke a northwestern Greek dialect and were considered for the greater part a (marginal) part of the "Greek world".
The Chaones are a different case altogether. They have Pelasgian roots, so its up to you if you consider them pre-hellenic or proto-hellenic (both suggestions are popular in certain quarters - feel free to discuss this if you don't mind hijacking your own thread). The first name of Epirus was Chaeonea so they were there before any other.
They are not the only Greeks of "pure" Pelasgic origins: The Eteokretes, several island inhabitants, the Arcadians and in certain quarters even the Athenians, are considered "of Pelasgic stock".
I mentioned the Athamanes before. Those are also a Greek tribe, although the "civilized" Greeks didn't gave them much credit, as they were more influenced by the "barbarians". On the other hand, the Dryopes, another of the tribes that inhabited Greek Epirus, were not of Greek origins.
They are related to the Leleges, those who started from Asia Minor and after driven out by the Ionian Greeks settled various islands, and areas in Peloponese and Epirus. So, those two tribes were not Greeks, although apparently they were Hellenized (the Leleges in the early classical antiquity, the Dryopes apparently much later).
Mind you, the Leleges/Dryopes have nothing to do with the Pelasgians, and certainly nothing to do with the Illyrians.

[Byzantine Prince]

The origins of the Epirotes are as complicated as the origins of other greeks. They most likely came out of the same movement of Doric tribes (hence their dialect of Greek), and remained in Epirus until the Romans destroyed the place and enslaved everyone. The tribes were many and they fought within eachother and with Illyrian tribes. The layers of history are mirky all over Epirus with signs of Illyrian and southern greek artifacts found all over.

They have Pelasgian roots, so its up to you if you consider them pre-hellenic or proto-hellenic (both suggestions are popular in certain quarters - feel free to discuss this if you don't mind hijacking your own thread).

I would say all ancient Balkan and Italian nations come from Pelasgian roots.