Quote Originally Posted by Carry2 View Post
In the same sense that stabbing someone does not make you evil, yes.
Degree, dude. Whether or not someone murders people is way more important for Goodness than whether or not someone lies is for Lawfulness.
There are conceivable circumstances that might justify stabbing another person, but by default, it is an evil-associated kind of act.
This default is less important than you think it is. If a character stabs an evil person in self defense after witnessing that person murdering a dozen orphans, that is pretty much not an Evil act at all. It's the character's attitude about it that tells you more: a Good person would feel remorse anyway, while a Neutral or Evil person wouldn't pay it any mind at all. Similarly, Tarquin lies to suit his purposes (and as I've argued before, not doing this is a really unnecessarily exclusive criterion for a Lawful Evil alignment) he prefers to do it in technical truths, and he keeps his promises, while a Chaotic person would lie willy-nilly without a second thought.

Likewise, deceit, manipulation
Deceit strikes me as more Evil (what Lawful Evil character is never deceptive?), and if you think manipulation is tied inextricably to Chaos,
you're obviously not familiar with one of a paladin's key class abilities: Summon Conscience.
rebellion
Conquering and rebellion are not the same thing.

and subversion of justice
You're conflating "justice" with "the law." Subverting justice is Evil, while subverting the law is Chaotic.

He keeps his promises only when it suits him
You gotta show some proof for this one.
I refuse to call this lawful behaviour.
Nobody's makin' ya, but I'm just not seeing your analysis. Could you give us a Lawful Evil character that does fit the alignment cleanly and explain how he fits it so much better than Tarquin?

Therefore, if one accepts that Tarquin can- as far as we ever see- preoccupy himself with Chaotic actions all the live long day,
I really think you're exaggerating here. There's not much of a point to the Lawful Evil alignment if we hold them to such rigorous ethical standards.

I cannot escape the conclusion that a character in D&D could preoccupy themselves with Evil actions all the live long day, often gratuitous, and still count as Good based on their avowed purpose and indirect ramifications.
As you may have observed, I take issue with your premises, so I do not come to this conclusion at all.
But from the perspective of the story, this is beside the point, because it's all off-panel, unspoken context. Someone actually reading SoD is not going to know any of this. (I suppose the head paladin mumbling something like "Let us be done here, and pray we may atone for our sins this day", would solve the problem neatly. But it's not in there.)
Someone reading SOD will probably just wonder how paladins can do such terrible things and then feel a bit sympathetic to Redcloak as the story progresses, and I imagine that was the point. Getting bogged down in the details of how the alignments work out, in my opinion, would diminish this effect on the audience; if we see penitent paladins that did these terrible deeds, we wouldn't sympathize as much with Redcloak's anger.

But this kind of depiction has, I think, the potential side-effect of encouraging role-play dysfunction when specifically tied to D&D rules.
I've never played D&D before, and I can tell you that if I joined a game (kinda hope I do some day!) the first thing I would do is ask for a thorough explanation of the rules from the DM. I really don't think this has nearly the problematic potential you seem to think it does.

I think it might be possible to maintain a consistently good story without encouraging dysfunction of this type, through either a more consistent application of alignment, or just not applying alignment labels. *spreads hands* IMHO.
My own humble opinion is that Rich has already succeeded in maintaining a consistently good story without encouraging dysfunction of this type.