exploration I can see, but social interaction I am not sure what you are looking for.
Does everything need to be codified and based on a dice roll, even you talking to merchants, guards, nobles? To me roleplaying works well for those situations, with the occasional skill check.
What rule support are you looking for here?
Rob Donoghue had a rant on twitter some time ago about how D&D worked well for combat, because while each individual action has some excitement behind it because of a rather swingy d20 roll, each action plays a fairly small part in the overall outcome of the combat. You can be fairly certain that even if I miss
this particular roll, that's not going to screw the whole fight over (and some of its combat weaknesses are things where a lot
does hinge on one single roll, like save-or-die abilities). But when dealing with out-of-combat challenges, that swinginess is bad, because it means that trying to persuade the baron to help out comes down to a single Charisma (Persuasion) roll.
That's the kind of thing that 4e-style skill challenges are intended to deal with. They were an attempt to transfer over the multi-roll nature of a combat over to an exploration or social challenge. In their original form they were kind of flawed, mainly because of wonky math, but the idea was great. And that's the kind of thing I would want to see in 5e revised.
Ok, hear me out... the world of the Nentir Vale pretty much steals the gods and locales of Greyhawk.
That's a bit unfair. The Dawn War pantheon has four gods I'd consider "exclusive" to Greyhawk: Pelor, Kord, Tharizdun, and Vecna. There are a bunch of others that I'd consider to be more pan-D&D, because they are the racial gods of various humanoids and other creatures: Bahamut, Moradin, Corellon, Sehanine, Asmodeus, Lolth, Gruumsh, and Tiamat – though the Nentir Vale generally makes changes to these to make them more generically applicable (e.g. Moradin is the god of Family, Community, and Creation, and he's popular among dwarves because those are the kinds of things dwarves value, but you'd also find craftsmen of other races/species praying to Moradin). Heck, there's even a Forgotten Realms god, Bane, who made his way into the pantheon.
but the Monster Vault dragons I believe are still more resistant to being locked-down/incapacitated due to the fact that they never run out of legendary resistance like the 5E dragons do.
Legendary Resistance is
meant to run out. It's not designed to make powerful creatures immune to crowd control, it's meant to make them resilient to it. I still think 13th Age's solution is better: put hp caps on crowd control spells, as that means you need to rough the targets up first before pressing the iWin button.
