((This was a multi-question ask, so I blocked out the other questions to keep this post focused. Plus, it was really fun to go through and redact things, lol.))
Not really… Of course, you’re free to interpret Thranduil’s character however you’d like, but there isn’t much in The Hobbit that supports this claim. Many readers think of Thranduil as greedy, and it’s all thanks to this quote:

In ancient days they had had wars with some of the dwarves, whom they accused of stealing their treasure. It is only fair to say that the dwarves gave a different account, and said that they only took what was their due, for the elf-king had bargained with them to shape his raw gold and silver, and had afterwards refused to give them their pay. If the elf-king had a weakness it was for treasure, especially for silver and white gems; and though his hoard was rich, he was ever eager for more, since he had not yet as great a treasure as other elf-lords of old.

Now, I admit, this whole paragraph makes Thranduil look pretty bad. But I honestly believe that the first half (the reference to ancient wars and conflicts between the dwarves and the elves) is actually a reference to Thingol. Since The Hobbit was written before Tolkien had cemented a lot of the Silmarillion stories, and certainly before he ever thought they’d be published, it’s very possible that he mixed Thingol’s story in with Thranduil. This theory is supported by the fact that, later on in the paragraph, Tolkien tells us that Thorin’s people weren’t involved with these old conflicts - if it wasn’t the dwarves of Moria, then it must have been the dwarves of Nogrod and Belegost, which were involved with the elves of the First Age.
The second part of the quote explains that the reason Thranduil is interested in gold is because he sees it as a measure of his worth as a ruler. He compares his own treasure to the treasure amassed by the great elf-lords of the First Age. It’s not that he wants gold and jewels for the sake of having gold and jewels. He wants it because he believes it will prove that he is a great ruler. So it’s not really pure greed (at least, not greed for treasure.) All in all, the whole paragraph sounds worse than it actually is.
Furthermore, Thranduil’s actions throughout the rest of the book suggest that he’s actually pretty willing to prioritize other issues over the accumulation of treasure. Yes, he responds to news of Smaug’s demise by marching straight for Erebor (where he thinks the treasure has been left unprotected.) But as soon as Bard’s messengers arrive, pleading for help with the wounded and homeless people of Esgaroth, he changes course and sends ahead food and supplies, arriving with his people to help rebuild the town. And later, when Bard suggests they attack the dwarves before they’ve had a chance to prepare for battle, Thranduil refuses, saying “Long will I tarry, ere I begin this war for gold.”
Basically, while Thranduil likes treasure (who doesn’t), he isn’t portrayed as caring for gold and jewels above all else. He is willing to put aside the promise of treasure in order to help his friends, and even to avoid a fight with his enemies/not-really-friends.
SOURCES: The Hobbit

No wonder all THIRTEEN Dwarves had such TROUBLE keeping on the straight and narrow of a simply straight path.

And thought I would post this blurb re Thranduil, as it contains one of the best quotes for me from the Hobbit, and I think we all want to hear LP say the line. Let us hope that PJ & co. are paying attention to the interest in Thranduil and Beorn!

More Beorn would be very nice, and I agree, the slightly weird brown eyes give him a good not-quite-human feel. Speaking of which, is it just me, or are they also making his eyes a bit bigger than normal along with changing the color?

More Bard would be great too! I really like what they've done with him.