Both statements I agree with quote]
You can't agree with both. They are mutually exclusive.
Call them what you might, a character with 68 hp never has to worry about being held up by a brigand with a loaded crossbow. He can confidently step up and snatch it away secure in the knowledge that it is impossible that he might receive any serious injury.
Well, within limits, correct.
It is this impossibility that troubles me. I like my heroes to still be human, and it is in their lack of god-like invincibility that their deeds are heroic. It isn't so much about what a high level character DOES or DOESN'T let himself do, it is what players do with their characters when they have enough hp to be cocky and reckless. They don't have to dance about avoiding anything, because they are safe and secure in their hp blanket.
And yet you just said, "So the low level bad guy should not be a challenge for a high level PC" You can't have this both ways. Either its a challenge, or it isn't. If it isn't a challenge, the PC will manage to defeat the guy with the crossbow/knife/shotgun/sword to the neck/gun to the back of the head, even though the bad guy got the drop on him, or else if it is a challenge the PC will find a different way to resolve the situation or die. Hense, in a system in which brigands with crossbows are a threat to high level characters, the DM is best advised not to spring brigands with crossbows on his PC's very often
or they will die.
And here I just plain disagree. I don't think that a 10th level rogue should have to take a bunch of feats to be lethal with a dagger.
Then you are wrong. Any character has to take a bunch of feats to be lethal against an experienced opponent with any weapon. That's the nature of the system.
Just the fact that he is 10th level should be merit enough to be dangerous with a dagger.
First, he is dangerous. He will probably win the fight against the thug anyway, and he's certainly a match for a dozen or more 1st level warriors. What he doesn't merit is being especially lethal with a dagger 'just because'. The game requires you to expend resources to be especially good at anything. Secondly, not he isn't. He's a 10th level rogue for crying out loud, not a 10th level fighter. If he wanted to be especially good at fighting he should be a fighter and not a rogue. A 10th level rogue without feats that enhance his combat ability is probably no better of a combatant than a 6th level fighter or so, and your thug is not far from that. It should be a fairly even fight, and cinematically even fights should not be over quickly. Anyone knows that if you want a rogue to be a match for a near level equivalent fighter in combat you have to take advantage of the one combat thing rogues do better than fighters - 'sneak attack'. So you ruling out sneak attacks was an attempt to coerse your example into a really bad one. I merely pointed out to you that with just 2 feats, not even really min/maxing, the game lets you do exactly what you said it doesn't do.
I have never known a rogue to take Power Attack...
Oh, brother. Like I said, your lack of familiarity with the game doesn't enhance your examples.
A skilled rogue doesn't make vicious thrusts into the throat - he should be able to make two or three well placed cuts that aim vitals AS HE FIGHTS (read: not sneak attack) because he's been there and knows where to cut. Slash the wrist, under the arm, behind the knee, etc - not dealing 1d4 each time like some tavern keeper NPC. So comes in the system where a high bonus to hit (skilled) translates into added damage proportional to how well the blow landed.
It sounds like you want to play a fighter.
I could keep up this conversation, but its pretty clear to me that you don't understand the implications on the design of a game if you implement it the way you say that you want to implement it. The fact is, D&D deals with the ability to generate alot of damage by the mechanisms of feats and iterative attacks. If you must, consider an iterative attack against a single foe to be a single swing doing as much damage as the total of all attacks. Feats are skill. Gaining iterative attacks are skill. Pure skill certainly does count. Having a character with both weapon finesse and power attack is an example of skil, and its in my experience really really common.
Think Lan from the Wheel of Time - its not wild Power Attacks that kill his opponents...
Oh bloody heck. How do you know? Lan doesn't have ANY stats. He's a character in a book. We have to come up with a game system for him before we know what a character like Lan has. Secondly, power attacks aren't wild attacks (or at least not necessarily). They are committed risky attacks. They are attacks in which the player chooses not to take advantage of some easy opening in favor of a much trickier - but much more rewarding - opening in his foes defences. Combat systems are abstract. All of them. You have to accept the abstractions if you want the combat to be resolved any time soon.