This is a welcome look at what impact his close bonds with mortals must have had on Legolas, and Thranduil's perspective gives a refreshing twist. I like how you've portrayed the Elvenking: concerned, loving, but also extremely practical and driven in the pursuit of what he believes is best for his son and people. Nice.
You've also tempered Thranduil's all-too-often-overblown mistrust of Men and Dwarves with some genuine insight and grudging respect for his son's friends and allies. And I particularly liked the line about Aragorn being more trouble than he was worth.
Good work.