I don't think the second paragraph that I've quoted has much to do with skilled play. I'm not aware of any evidence that swashbuckling chandelier-swinging was a big part of Gygax's RPGing, and his rulebooks don't offer any advice on how to adjudicate it (and the rules for thief-acrobats don't really help in this respect).Sure, sometimes the mechanics can provide a safety net, but they can also have a negative impact on skilled play. The more mechanics that are available, especially for things like searching, the more likely the GM is to lean on those without a lot of consideration. That can make it more difficult to to engage in the kind of action declaration and adjudication that really makes skilled play hum.
<snip>
An example that works to illustrate this, if we want to step back from searching for a moment, is classic swashbuckling action like swinging from a chandelier. The more crunch you have, the more discrete and defined rolls and whatnot, the more obstacles can be placed in front of a character who decides to declare that action.
Conversely, I still have a clear memory of a Rolemaster session where one PC with good physical skills was beneath the deck of a ship but jumping up through a hatch to release arrows like a jack-in-the-box. The rules about how high the character could jump were clear enough, and it was easy to apply his Acrobatics skill as a percentage of his available bow attack bonus (a standard technique in RM). I found Rolemaster more apt to support this sort of thing than AD&D (of course 4e D&D was better again for it, but 4e is hardly a low-crunch game!).
Turning to the first paragraph, searching/perception does seem to occupy a special role in skilled play, because central to skilled play is the players learning the truth about their PC's fictional circumstances, which has been pre-authored by the GM, by declaring actions for their PCs that will oblige the GM to reveal that truth as part of the narration of the outcome. If you make that too cheap, then the "skill" is lost and it just becomes a lottery (or a give away). But what is key to this is not the way action declarations are resolved, but what is required as part of their framing. AD&D is replete with "perception checks" - rolls to find secret doors, to listen at doors, to find traps, etc - and the actual play report from the ToH convention (by a clearly very experienced skilled player) expresses irritation with how those were adjudicated in that game (which tells us that they were hardly anathema back then). But I search the room is not generally treated as a sufficiently precise action declaration to trigger a check. I think it's hard to specify, in the abstract, the requisite degree of granularity, but it's closely correlated with received understandings of the level of detail the GM is to use in the map-and-key. So I search the lock for traps is specific enough, as is I search the west wall for secret doors - because it is understood that doors are detailed at least down to the granularity of their latching mechanisms, whereas door-free walls are not generally detailed beyond their existence in 5' or 10'-long lengths.
3E D&D's skill system is often put forward as a contrast with skilled play, but as far as I can tell the underlying issue is not the existence of a skill system, but the particular approach to framing and resolution that seems to have become typical in 3E. A number of 3E's skills seem not to require the player to actually commit his/her PC to a move within the fiction, and rather just serve as "reframing" devices - using Perception checks to just oblige the GM to tell the player more details about the situation; using Diplomacy to reframe the situation from one with a neutral or hostile PC to one with a friendly NPC; etc. This is completely at odds with skilled play, because it's about bypassing rather than engaging the fiction.