@ Veekie
not really, so a martial artist may know specific techniques, and may learn maneuvers and such specific to his style, but the general "Combat awareness" that you gain only comes with experience.
Experience counts for something. If you have the training necessary to be a black belt, but have never fought somone, even if its with pads or such, you will always be less effective as a fighter than one who has fought hundreds of fights.
the experience you get lets you "level up" in a way, such that you gain a sense of how to move in combat, how to dodge effectively, how to block and counterstrike.
if we proceed on the assumption that the level one fighter has basics teaching and nothing else so they are equivalent to ~yellow belt or one step up from white, lets say the purple/brown belt is the level 8-12 fighter, and the black belt is the 12+ expert level fighter (using an American style belt systems which is flawed but gives us a point of reference). then it actually makes sense that the level one fighter isn't really good at any of the things you mention in combat.
As one who has trained in and instructed martial arts I can give you examples:
Yellow belts: even though they may know how to throw a punch they rarely have the speed, or accuracy to hit with it, and since they have just started they still aren't in the physical shape it takes to throw a particularly devastating punch-unless they were in shape to start with, (and in that case they have another class compared to a normal commoner and aren't level 1). Even if they do have the strength, their blows are typically so predictable and slow that they cannot connect against an expert fighter. Kicking is usually still so inefficient and slow that it is laughable, so much so that they shouldn't even try but for the fact that they will only learn by doing. They are basically a fighter with few to no feats.
Maybe they have some promise in a few areas, but generally they still suck, almost to the point where a commoner could still beat them if he got lucky.
-Improved Unarmed Strike? no, not at this level, again yellow belts only know the basics
-Combat Expertise, no, this is only learned by experience, and this level doesn't have it
-Power Attack, they are still struggling just to hit, they have no idea how to pull or push strikes.
-(in PF) Deadly Aim, they don't have time to aim, they're too slow
-Improved Trip/Grapple, a yellow belt falls on his face 9x out of 10 trying to trip or grab, they just don't know what to do yet
-Two Weapon Fighting, a yellow belt would more likely hit himself if he tried to wield two weapons than his opponent
purple/brown belts: typically do one thing very well, they are on the verge of becoming good fighters, but they still make costly mistakes in actual combat. An expert fighter could have trouble if they attempt to challenge this fighter in his specialty area, for example a brown belt could have particularly powerful or speedy kicks, or a punch that is difficult to avoid, however they don't have a range of skills perfected. Usually the expert fighter will defeat them by picking on their weakness- maybe ground fighting, maybe their kicks are better and they stay up and at range. At this level the intermediate fighter can hold his own, but doesn't know how to win in every situation. these are fighters with a few feats, maybe they've specialized in something, or maybe they've taken feats that have kept them versatile in many areas, but don't have enough to be truly good at most.
-Improved Unarmed Strike? maybe, if this is what they are focused in
-Combat Expertise, Probably, at this point they've learned to defend at the cost of offense...
-Power Attack, May make sense, if they have perfected a swing well enough to manipulate the speed and strength of the swing
-(in PF) Deadly Aim, maybe, if they've been given an opening that fits their skill
-Improved Trip/Grapple, probably not, this is more of an expert technique, because its free, the intermediate fighter is just starting to learn how to trip or grapple, they aren't advanced enough to combine attacks, combos sure, but punching and grappling with the same hand is something they are just beginning to learn
-Two Weapon Fighting, Sure, as long as they have been training with the weapons in question
Black belts: Experts; these fighters have learned the theory of how to handle themselves in most or all combat situations and have put it to the test in actual combat(or practice combat) Additionally, these fighters have generally trained their bodies to react without the need to think about it. One doesn't just learn the theory of martial arts, you really become good through thousands and thousands of practice points, kicks thrown, punches delivered; forms of movement mastered. This is why forms are so important in martial arts, even though American styles tend to gloss over them. Forms are there to help your body master the basics, then the truly masterful fighter can freely let their body "flow" through all kinds of combat, without having to put much thought into it. the expert fighter is usually very good at one or two areas, and can handle themselves quite well in most areas.
-Improved Unarmed Strike? likely, by this point they've gained a knowledge of how this works regardless of what they have specialized in
-Combat Expertise, yes, but this should be better, the expert has learned to defend and attack at the same time
-Power Attack, should be able to make this kind of strike with any technique he has perfected.
-Improved Trip/Grapple, yes, this is the level where you really learn to trip and grapple...
-(in PF) Deadly Aim, Yes, usually very deadly.
-Two Weapon Fighting, Sure, and usually have enough experience with it to pick up different weapons without difficulty.
For me, it seems the fighter is actually pretty close to realistic. whats wildly not realistic is the wizard who can do some crazy reality breaking things at level 1, whereas the fighter is just a yellow belt...