I keep wondering exactly how much knife/ stick training is really necessary for the real world? What are the chances I would run into an expert in this area trying to kill me? Better yet, how much skill does it really take to be able to stab someone or be able to hit them with a stick?
An untrained person with a knife is extremely deadly, even to a highly trained individual. Someone who is fast and dedicated is going to be hard to handle. An untrained person with a stick gives you a little more room to maneuver, but a drunkard with a baseball bat will still give you a heck of a time. It takes very little skill to be deadly with these weapons (esp. the knife, though the reach of the stick generally makes it a superior weapon in skilled hands).
It seems as though, in my extremely limited FMA experience, FMA training is really designed to go up against another skilled FMA'er?
Answering this is difficult. The FMAs evolved for real combat. Many take an offensive attitude: If you attack me, I attack you back! Remember first that if you must face the knife, knowing what it can do is important. Where I study JKD, even senior JKDers often say to me "I didn't know you could hit me from that angle with the stick!" Experience with the weapon matters. Your average street thug knows relatively little about the knife...
but he knows 2-3 tricks and that's enough for the one time he faces you. These tricks are traded by gang members, in prisons, etc. They will know
something. Training in the FMAs prepares you for anything (but there's no guarantee you can make it work when you need it, sadly). A little FMA training will open your eyes to the possibilities of the knife, making whatever other training you engage in that much more realistic.
But many FMAs have gone further. They have developed counters to their own counters. It isn't a game: Like in chess, the winner may well be he who makes the next-to-last mistake. (With knife vs. knife, both sides can lose, of course). It improves overall skills...sensitivity, ability to pick up on surprising lines of attack, ability to flow from one situation to the next, etc. Even if you never use anything more than a simple defense, training for a higher level increases the odds you can successfully perform at a basic level under stress.
Some arts have taken it further. There are stick-fencing arts that are so intricate that it does indeed seem as though only a fellow high-level practitioner of the same art could even throw the technique that would let you pull off your counter! Balintawak Eskrima comes to mind. We always warn people to avoid the "fencing/dueling" mentality if they're interested in self-defense. Tehre's nothing wrong with practicing the arnis version of kendo, but one must be clear about it!
Some people say that you must be prepared for three types of opponents: An untrained fighter; a trained fighter from a different system; and a trained fighter from your system. If you believe that, then starting with simple defenses and progressing is good. In JKD we very much train for different types of fighters: The wild swinger, the boxer, the kickboxer, teh grappler, etc. In the FMAs we generally consider first the untrained knifer/stickfighter, and then progress to a more skilled opponent, and ultimately many arts look at how to counter their
own techniques. So I would say that No, FMA training is not designed to soley go up against another skilled FMAer, but that at the higher levels you do learn that also. But it's a good reminder that you should work with beginners at your school and cross-train with others when possible.
I can't emphasize strongly enough that the average street criminal knows more about the knife than you think he does. His training is not systematic, but if he's still at it then it's effective. He knows how to distract you to set up (his or his accomplice's) shot; he knows how to get in a fast and effective strike; and he knows how to handle a simple "arms up" counter. Don't underestimate him. If he's been to prison, he's been in and survived a knife culture.
Short answer: I'm biased, but I'd recommend training with an FMAer for a few months. If you haven't, you probably don't know how much you don't know about what the knfie and stick can do. A few months of this will pay life-long dividens as you judge the usefulness of knife defense techniques taught to you in other arts.
Good luck.