4e D&D is not rigid, in my experience of it. That seems to be something you're bringing to it.
No, from all your accounts, you are barely playing 4e, you ignore most of the rules and transform fighting a tough boss in 3 rolls that the boss cannot even make (probably because you realised that there was no way for the PCs to even scratch him at the time). This has nothing to do with the way 4e has been written. The rigid rules (once more, explain to me how you can only hop on the battlefield and not truly fly ? Ah yes, because 4e is totally incompatible with 3d) don't cause you a problem, since you ignore them, so you don't have to maintain the consistency.
Good for you if it's the game that you like, but honestly, claiming that it's because it's 4e leaves me baffled.
As for Skill Challenges, claiming that having a formal structure enhances creativity is like claiming that driving like when you passed your license enhances your chances of success driving in Mad Max. Although, with the fact that you ignore the rules probably means that it's as free form as it can get, but then again, why the structure ? What does it bring ?
You are the one who seems to be bringing the rigidity! A dangerous precedent? Some of us call it playing the game.
And I've never seen a game of 4e played that way. I'm not even sure what it brings being 4e.
I can't remember now whether the players generated some effect that allowed the paladin to hang onto Ygorl as he teleported; or whether Ygorl was deliberately holding the paladin to him as he teleported. I know that Ygorl was dragging the paladin through waves of chaos and entropy as he teleported: mechanically attempting Arcana checks to inflict damage.
Yeah right, a boss with 25 intelligence preferring trying to roll arcana checks against a DC of 40 (and failing miserably three times) instead of using any of his awesome powers makes total sense. There are effectively reasons for him having at will teleport (at least the ridiculously underpowered version of 4 which is like a misty step) and phasing.
Makes total sense in the narrative,
Part of skilled play is using the fiction - as
@Ovinomancer and
@Campbell have mentioned.
That's not the way other people define it, and again, I'm pretty sure that I would not feel very proud of bringing Ygorl down in terms of skilled play if played like you did. And what narrative ? Oh yes, I'll grapple something that looks like this and is a lord of entropy ? Really great idea.
In the context of 4e D&D at Epic tier, that fiction includes the cosmological context in which the PCs - including a demigod, a Sage of Ages, an Eternal Defender, an Emergent Primordial and a Marshall of Letherna - are operating. Engaging with Ygorl, grappling him, holding onto him - and then trapping him in the Crytsal of Ebon Flame - is what the game is about.
Not in my games, it's not, because how do you grapple a being more or less made of smoke, who can teleport and phase ? Come on...