Interesting thread, although I confess to not having read the entire thing. However, I'm prompted to make a comment on the "narrativism" of 4e that I know probably won't satisfy some folks, but I feel it needs to be said anyway. Forgive me if it's completely redundant...
Fourth Edition separates, rather drastically, player choice from character choice, especially when the martial power source is involved. What do I mean by that? Let me give some examples.
Martial Daily & Encounter powers: Almost by definition, there is nothing stopping martial powers from being used repeatedly. Hence, most characters would do nothing but use their "best moves" constantly. However, this doesn't fit with what we see in fiction or even reality when it comes to swordsmen and martial artists.
Most trained fighters have a few relatively straight-forward moves that they can pull off all the time. In addition, each usually has some signature "special moves" that are highly situation dependent. This is objectively true. Once you acknowledge this, the question becomes: how do you model such a thing in a GAME?
Option 1) Leave it entirely up to the discretion of the referee what is "allowed" at any given time.
Option 2) Go strictly simulationist, and allow the player to use the power whenever the situation is correct. That means the DM describes the situation ahead of time, works out the physics, and fusses over the exact mental state of the player's opponent from round to round.
Option 3) Give the player a power that he can build up to by having his character take certain actions to set it up. This puts the enabling move into the player's hands, but feels like the character is doing something.
Option 4) Give the player a power that he can choose to use at any time, but only infrequently. In the game world, the character is only aware that he's gotten lucky or fortunate. In other words, things have "worked out" for him.
Mostly, this is a matter of Agency (or "Narrative Control"). Who should get to decide when the character's cool powers come into play? The DM? Or the Player? Without going into a long, exhaustive discussion, let's just say that old school D&D (OD&D thru 2e) opts for Option 1, 3e leans to Option 2 (or 3 kinda), and Fourth Edition fully embraces Option 4.
In addition, Fourth Edition offers guidelines to DMs (the aforementioned p.42 of the DMG) for how to handle situations the rules don't cover with the DM's permission. Older editions of D&D could have benefited from guidelines like this, but they weren't there - because Gygax and co. pretty much thought that any experienced player would want to play a magic-user - so cool stunt mechanics were unnecessary.
D&D (up until 3e) has always been more "narrativist" than "simulationist." Especially on some things - if you want to be bludgeoned over the head, read Gary's 1e discussion of "what hit points represent." Now, to be fair, it's also quite "gamist." Unlike many "narrativist" games, players don't have a lot of control over the game world (although this can vary from group to group). And 4e still remains simulationist enough that the setting of an encounter is still largely determined by the DM. In a truly narrativist game, there'd be no issue with a martial controller, because the player could just decide that there happened to be difficult terrain in a particular section of the battlefield. It just wasn't hindering anyone until the player brought it up.
However, that's just a little too much "flexible reality" for most D&D groups.
There's not really a "better" or "worse" here. There are just different styles. Personally, as a player I like having more control over what I can do, and as a DM, I like giving my players some predefined options they can use.
When they come into play, "Stunts" like those presented on p.42 should be viable options for a PC to use - meaning they should be comparable to using his powers - the "Rule of Cool" certainly applies here.
However, I freely admit that I'm glad that, absent player stunts, Fourth Edition doesn't default to "Ok, I whack him" or "Okay, I shoot him." Which IS what, IMO, what tends to happen in early editions.
And if I have to jump through some corner case hoops or come up with a few "narrativist" explanations to make that happen, I'll live.
Obviously, opinions differ, YMMV, and all that...