There's a line that has been drawn here between so called "modern" martial arts and "traditional ones". Perhaps I can help clear this up.
The modern martial arts (BJJ, Krav Maga, Systema, etc) are effective, and they are effective, to a point, from the first time you learn them. The attraction of these systems is that they do not require years of training to be able to defend yourself using them - which is why these and systems like them are taught to modern police and military. However, these systems can be limited in their adaptability.
Traditional martial arts ( a term I'm using loosely- I'm speaking of traditional jujutsu, kung-fu, etc - I am not a proponent of Aikido, modern TKD, etc) can be extremely effective, and when they are grasped up to a certain level, will often times be more effective than the modern martial arts, becuase these systems are HUGE and study the principles of actual combat to a deeper degree - IF you put the time required into them. The caveat, however, is that it will no doubt take you several (at least 3-4) years of steady training in these systems to truely get a solid grasp on the concepts and be able to use them in a real engagement. Traditional martial arts are very much "you get out what you put in".
On the issue of kata. I can tell people who dismiss kata as useless have not put the time into their martial art as to really understand them, or have not been instructed properly. Traditional kata are designed to teach you a PRINCIPLE, not to be used in actual combat. I fear for the person who takes that approach and trys a pre-designed pattern upon a living opponent.
Personally, I train in traditional ju-jutsu which includes ground and standing fighting, striking and grappling, among other things. But several years ago when I had only been training for a year or so, I would have hesitated to proclaim my ability to defend myself with the methods, as I had not (and still do not, to a lesser extent - we are all still learning) grasped the methods and theories. Do what you enjoy and what you have time for. My martial art is a huge commitment, and I will admit that I firmly believe I could defend myself in any engagement becuase of it; simply because practicing my martial art and polishing my skills as a warrior is how I choose to spend a good deal of my time.
As far as fitness vs. martial art: strengh is useless without technique, and technique is useless without proper strength to apply it. Look at Bruce Lee. An incredible martial artist, he was a stern advocate of western training methods as well. I would highly reccomend "The Art of Expressing the Human Body", which covers Bruce's weight training methods as was concerned with his martial art. You may be strong, but you also must know how to properly apply your muscles to gain the maximum benefit and efficiency from your technique.
Fighting spirit will kill you in a fight. Idealy, you should be able to remain logical and rely on your techniques. What if, when you are so enraged and are brawling with an opponent, another picks up a chair and runs over to you with the intention of harming you? A true, confident martial artist will be in a state of mind to direct his attention to the bigger threat, deal with it, and carry on accordingly. Peak awareness at all times during a fight is absolutely nessecary.
The complete martial artist will train in technique, strength, endurance and flexibility. Letting any of these slack is to fall short, and your life may one day depend on any or all of them.
Good luck in your training!
