'classic D&D' doesn't really have per-encounter resources at all. The main party resource, spells, are always per-day, as are hit points (essentially).
hps were a per-day resource because healing spells were a per-day resource, if considered separately, it could take weeks to recover hps - it never did, it was a non-viable mode of play if any rival out there were burning spells every day.
I can't think of a good example of a per-encounter resource in AD&D at all, beyond maybe "thieves can only backstab once per encounter", but even that's not a hard rule, just an expected fictional limitation.
There were the odd 1/turn magic item or special ability, and a turn (at 10 minutes) usually encompassed an encounter, with the DMG assumption that the balance of the 10 minutes not spend fighting would be spent resting, binding your wounds, and fixing up your kit so you're ready for the next fight. So 1/turn was essentially 'encounter' back in the day, not that that counts for anything.
But 4e is MUCH less a per-day gated game, and much more a per-encounter gated one than other editions of D&D.
Even so, 4e was a per-day 'gated' game, too. And, it didn't have the weeks-to-recover-hp disconnect, since hps & surges were also daily resources.
The main reason you could vary pacing wildly in 4e without screwing things up too bad was that the classes had comparable resources available, regardless of pacing. So the 5MWD made that sole encounter a good deal easier, but not a caster-dominated fiasco.
In 4e you can certainly continue to operate, even with many resources largely depleted. You get your encounter powers back, you have milestones which allow recouping of APs, and many item powers/properties are usable on either a continuous, at-will, or encounter basis. Its true, HS puts a cap on your day, eventually, but the limit is generally high enough that its more a question of management vs continuing until its expended.
In a true "encounter based" game, you wouldn't run up against that. A closely related example is the 7th ("D&D") edition of Gamma World, in which there were no surges, you simple recovered all your hps with every short rest. There was one 'daily' in the whole game - probably a misprint.
4e seems to be all-in for transparency in combat, though there have been discussions around things like "are minions declared as such or just described and its left to the players to figure it out" or "do you tell the players the monster's hit point totals" etc. The same question of course can be asked about SCs. My opinion is that the players are collaborators and its fruitless to keep things from them unless there's a really interesting reason to do so.
4e certainly can work either way. IMHO, it works more smoothly with everything open and above board. (I'll tag minions as such, and generally give away approximate level and elite or solo, too - though, the way I see it, 'elite' or 'minion' is not really something the monster /is/, it's how the monster stacks up to the party - but, I won't give hp totals up front: I figure if the party pays attention to how much damage is accumulated and when it's bloodied, they'll have a pretty good idea, anyway.)
Skill Challenges are just a tool and are not mandatory. Even within Skill Challenges, you can have many scenes that don't use die rolls to resolve or have it overarch an entire adventuring day or even longer.
They're just a narrative structure designed to get everyone involved and have meaningful, consistent definitions of success. There's no need for die rolls with most NPCs within a skill challenge. You talk to the librarian, she answers your questions. Don't go in the right direction in terms of questioning her, she might not give you the piece of information you're looking to get. And that might affect what direction the skill challenge goes.
The SC structure does seem to be very much oriented on the PCs for resolution. It just assumes what the NPCs will be doing, whether the PCs are acting and the NPC re-acting, or vice-versa, it's the PC actions/checks that determine success or failure....