I was about to address similar issues in your previous Mirkwood topic, but this one now looks the most appropriate for such type of feedback.
First of all, let us start with the concept:
Personally, I like every single suggestion, and I totally understand why, in your opinion, two of the current abilities need to slip in lower slots, being therefore available earlier. Really, there is not much to add to your work. On a literary, lore-based perspective, I fancy how his level-7 ability references his battle against the evils of the North. If I'm not mistaken, the Woodland King was well alive in the First Age, as he was (very likely) a Sindarin prince at the court of Elwë, in Doriath. Very significant connection
Nevertheless, I would like to point out something, which I've been pretty fixated on for quite a long time. It's a kind of atavistic issue that keeps me awake at night. In front of it, changes on abilities or strategy move to the background of the holistic portrait. The problem I have with him is probably caused by an ill combination of his skills, but not solely because of his current power set. It's quite simple:
I just don't like him, as a hero.
It's the same with Lothlórien's current scout heroes. I don't like him. He looks slow, clumsy and sluggish. He should be as skilled as Elrond or Celeborn. A veritable master-swordsman, versed in the secrets of all blades. Agile, rapid and lethal, just as he swings his sword in DOS. Plus, he's a natural-born leader, since he rules his realm with an iron fist and in all occasions defended the borders against any sort of menace. Whenever I play with him, I see very little of a king, neither of a deadly warrior.
I get that much energy has been poured into his design. That's apparent, given the array of unique features. Only, uniqueness cannot always make up for flaws, or automatically transform a hero in a legend. I perceive it clearly: there seems to be something that doesn't work.
I might be completely misled, but I blame his current animation at large. It may have been the most viable choice, yet at what cost? The two aforementioned Elven sires are utterly amazing; though assigned to different roles, they do splendidly in battle. On the other side, I can barely move Thranduil around, without having the chance to prove his value. Again, we're talking about different roles and functions, but the comparison with his two Elven fellows is quite unforgiving, if you ask me.
I hope there will be room for a possible (needed) overhaul; not so much dissimilar to what has lately befallen our White Lady.
Concerning the last proposed ability, what doesn't seem to fully convince me is the fact that Palace Guards happen to be everywhere in the game. Theoretically, they should embody an imposing elite unit, and this they do beautifully. No complaints, except that the player may easily recruit battalions upon battalions of them. There's no limit. Wherefore, are we really sure that a shield wall (made entirely of such unit) could be enough unique for an ultimate feature? I believe there might be some differentiation problematics, there.
Additionally, Aragorn's own phantom wall already brings in the Mod an akin concept, even though its main purpose differs substantially with that of Palace Guards. I like the idea nonetheless, as it should explore his commander-like side, and we know that the Woodland King wages war only in very rare situations, when the own safety of the woods is in peril.
Said that, that's where the lancers from the Hobbit come to the rescue!
What about allowing him to temporarily summon a host of those lancers, ordered in a very tight, strict formation, so to form a quasi-impenetrable wall. This is shown in the extended edition of BOTFA.
It should create a vast and long wall of pikes and shield, not for his personal protection, but for the sake of your very army. It can either be stationary or movable, albeit very slow. Also, it would sort of resemble the testudo formation of Roman legions, symbolising Elven warfare tradition and severe discipline, against lesser adversaries.
(From 4:04)
https://youtube.com/watch?v=TpsFWBzDHkk