if you're putting untelegraphed traps in your dungeons to establish a mood, and the optimal player strategy for safely dealing with these untelegraphed traps spoils the mood... I dunno, doesn't seem like a very effective approach to the stated goal.
Like I said, maybe the idea is that players play PCs who fit with the mood, and the GM picks up and manages (perhaps manages away) all the potential adverse consequences.
I haven't got REH's The Scalet Citadel in front of me, but as I recall it there are two main traps/hazards: there's a pit, which Conan avoids falling into in the dark due to his uncanny senses (in game terms, this could be some sort of Perception mechanic at work); and there's the hell plant, which - as best I recall - Conan defeats by dint of physical prowess (in game temrs, this could be resolving some sort of check or series of checks to eliminate the triggered hazard).
A GM who drops in traps and hazards at (what s/he takes to be) a dramatically appropriate frequency will not purge players who play their PCs like Conan. There'll be the occasional narration of the noticed trap (like the pit) and there'll be the occasional stumbling into a trap/hazard (like the hellplant) which the PCs defeat without debilitating downstream consequences for their prospects of success.
And if the struggle against the hellplant looks like it
is being more demanding than was intended by the GM, then in the approach I'm describing here the GM might manipulate things "behind the scenes" to compensate - whether reducing the threat posed by some later planned encounter, or fudging one of the checks made to deal with the plant, or whatever other device this sort of GM has up his/her sleeve.
I personally don't play in the style I've just described - in a different current thread in General, I've been discussing (with [MENTION=6801228]Chaosmancer[/MENTION] and others) what I think are ways of getting the REH-like dramatic pacing and consequnces but with less reliance on GM-side determinations. But I think that the sort of approach I've described in this thread is a widely-adopted one. I'm hesitant to project my own account of the approach too readily onto individual posters each of whom has his/her own unique way of playing RPGs, but with appropriate caution and no intention to cause offence, I would conjecture that [MENTION=6801228]Chaosmancer[/MENTION], [MENTION=6801845]Oofta[/MENTION] and [MENTION=6789021]Yardiff[/MENTION] can all recognise some aspects of how they approach GMing in what I've set out in this post.