Questions concerning Thranduil

[The Saucepan Man]

A personal belief of mine is that Thranduil and his people are the descendants of Doriath Elves

Thranduil's father, Oropher, was a Sindarin Elf from Doriath. And it's likely that there were other Elves in Thranduil's realm who were originally from Doriath. But, I believe that most of them were Nandor, or possibly Avari, ie Elves who never crossed the Misty Mountains and entered Beleriand.