Fencing uses positions/stances, though they don't have flowery names.
I've got about 30 weeks of fencing training so I'm no expert, but I have to say, 'Not so much'. Fencing basically uses one stance, 'One-handed fighting'. There are some older schools that used different stances, and they are not surprising things like 'two-handed fighting' (Florentine, sword & dirk, etc.) and 'sword and board' (sword and buckler). Longsword has a couple of stances, but you aren't expected to fight in them, they are more like opening positions in chess in that you are trying to set the mode of the engagement when it begins. Again, those stances are about openings, drawing out an opening, and faking an opening when you believe that you have the capacity to close it unexpectedly.
Interesting concept, but I think the best overall system would be one that combined both offensive and defensive maneuvers - then you could play a "pure offense" fighter (two-hander), a "pure defense fighter" (sword/board), or something in between.
I don't think you are getting it at all. Some 'counters' would be offensive in nature - you exploit an opening to make a strong attack. Put into the language of D&D, they might be something like:
'Beat Down'
"If you score a critical hit, then if your next attack in the same round hits the same target, it automatically threatens a critical hit."
-OR-
'Watch your head, fool'
"If your opponent attempts to trip you and fails, you take advantage of the opening to attack his exposed head and neck. You may make an immediate attack and if it succeeds, it automatically threatens a critical hit."
-OR-
'Back and forth'
"If you are flanked, you may lunge at one of your flankers. If this first attack succeeds, you may immediately wheel and make a full attack on the opposite flanker."
Or whatever. I'm just making these up as I go.
In fact, in Western combat there is very little distinction between being on offense and being on defense. Every defence is expected to have an accompaning attack. In fact, a defensive style is defending yourself with attacks - in fencing this is called 'intercepting' and in boxing 'counter-punching'. Likewise, boxers are taught to defend themselves with flurries of jabs. Still, defensive manuevers might be:
Parry
"If you are attacked and the attack succeeds by 4 or less, you may spend an available attack of oppurtunity to counter the attack."
Or
Wary Combatant
"You aren't easily fooled twice. If an opponent has attempted a trip, bullrush, [insert long list here] already in this combat, you gain a +5 bonus to counter such manuever if they use it a second time."
The main thing is that:
1) These would be used 'at will'. If you knew how to do them, you could use them in every circumstance that they applied. You don't forget how to do them to learn to do something else. You aren't rendered unable to do them just because you used them a second ago.
2) They aren't Vancian spells. You prepare a certain number that you know for the day. You have access to all of them all the time.
BTW, isn't a counter just another variation of "hitting something"?
Yes. As I said, its not combat that is really the problem. The above stuff is just 'frosting', and if it makes combat more interesting for you and the fighter less boring then great, but it doesn't make the fighter more playable.
It just requires specific conditions to make it work, which makes it less useful than an offensive maneuver, which is useful all the time.
Yes. Situationally useful is not only more realistic IMO, but it balances against the assumption of useable all the time that I'm insisting on to avoid the spell-like flavor that ToB uses to achieve balance with something that is selectively usable. So I say, "You need specific conditions, but you can always use it." as opposed to, "You can choose when to use it, but you can't always use it." In practice, both systems might end up with roughly the same number of 'times you can do something extra', but the flavor is very different.
Losing the action economy: The fighter needs more defenses against things that steal actions from him. Some of this has to be done at the spell end, for example by giving force effects some (not necessarily alot but some) vulnerability to mundane damage, by making save or die have a built in 'second chance', and so forth. Some of it has to be done on the fighters end, for example by giving the fighter SR against targeted attacks at high levels, by giving fighters defenses similar to (but not copies of) the rogues defences like 'Improved Evasion' and 'Slippery Mind', so that it isn't not as easy to take the fighter out for a long period. I've been trying to do this with feats, however, if the fighter needs any class abilities at all, this is where I'd be going because at high levels the need to take defensive feats to stay in the game becomes essentially a feat tax.
All the above combat manuevers are fine as feats or base manuevers (trip or disarm, for example, in the RAW). For example, parry is a base manuever in my game, and you can take feats to improve it. All of your combat style class abilities are fine as feats. If you really want to silo some abilities for the fighter, I can see two areas: defensive abilities ('parry spell', 'improved mettle', whatever) and bonus attacks of oppurtunity (so that you don't have to be high dex as a fighter to heavily participate in the 'attack economy').
Invisibility: A fighter has decent ability to deal with invisible melee attack through high AC and the blindfight feat. However, its got poor ability to detect things at range and/or deal with surprise. It needs some sort of compensation, although I'm not sure what as 'uncanny reflex' is more the rogues schtick. My general thrust would be toward the fighter being better than other classes at guessing the square of an invisible foe, and I'm open to mechanical suggestion. Again, this is the sort of thing that I'd expect to see make 'class ability' status, not bonus feats in disguise.
Weapon Dependancy: A fighter is in much more serious trouble than any other class if they lose their equipment, especially at high levels. A mage still has his prepared spells. A cleric can get by. A sorcerer might not even be particularly disadvantaged. A fighter needs better ability to be the cool rather than his equipment.
Addionally, the fighter needs more abilities to 'be cool' other than hitting things. In particular, I think you ought to be able to build a 4 edition style 'Warlord' and do some measure of battlefield control with a 3rd edition fighter.
Finally, this isn't an improvement to the fighter directly, but the DC of all effects at high levels needs to decrease across the board. Your attempt to fix the problem by making the weak save advance relatively faster doesn't address the real problem, which is, at high level, even your good save isn't necessarily that good without min/maxing your magical defenses because the ability to increase the DC of an attack outstrips the ability to increase the save. It isn't just that its almost impossible to make your bad save, it's that your good save still fails a significant portion of the time. In high level play, this is unacceptable because the consequences of failure are becoming higher and higher as the effects become stronger and stronger.