I recently started watching Kuroko no Basuke and have watched it up to episode 5. The skills shown up till now are ridiculous. Can those skills be achieved by people in real life? I'm taking about physical abilities like speed, jump, agility, etc., not stuff like the Phantom Pass.
Seeing as you're on episode 5, this is going to have spoilers.
While the "Misdirection" which makes him invisible is probably at least rooted in reality, I don't think it can be taken as far as the TV series makes it out to be. It would be one thing to misdirect someone who's defending, but to make yourself invisible to people watching from the crowd or the bench is a little bit incredulous.
The "Invisible Pass" is something that is described as more of a "tap pass" and it uses misdirection. That's probably something that people do in real life, though again, maybe not to the fantastic results we see in the show.
The "Ignite Pass"/"Ignite Pass Kai"/"Cyclone Pass" are probably things that you could see basketball players do, but the way they're animated and the speed in which they're shown in the show makes it impossible in real life.
The "Vanishing Drive" is another misdirection, and like the first invisibility misdirection, it's probably something people can do in real life against a defender, but everyone else in the arena would obviously still be able to see the player. In the show, it makes it seem like Kuroko goes right through the defender for everyone, not just the defender.
The "Misdirection Overflow" is clearly something that can't be done in real life given how spectacular the effect can be. The explanation of how this trick works isn't sufficient in making players "disappear" and trick everyone. Stuff like this make Kuroko seem more like an illusionist instead of 1 among 10 players on a court.
The "Phantom Shot" is really just an odd way of shooting the ball. It's something people can surely do in real life, but why would they if they can shoot normally? It's unique in the show's story because Kuroko can't shoot.
I think that's as far as they've gotten so far in the anime.
Many of Aomine's formless shots are unachievable outside the realm of lucky. Midorima's shot arc is excessive but the half-court shot (without the crazy arc) is within reason. Murasakibara's quickness and speed can be explained, but that crazy power with that body frame is insane. Akashi's emperor eye. A good eye, tons of experience, and athletic ability. Kise's Copy... well, there's plenty of people out there that are like that. The zone is explainable, but the reasoning on how it can be "tapped" into (in the anime) is dubious.
My two cents on Kuroko's misdirection and Misdirection Overflow:
Most coaches and players define misdirection as putting their attention on themselves to create space for others (which is Overflow). Kuroko's misdirection if applied in real-life only allows for, at most 3 1/2 feet of separation. It's almost unbelievable to shake somebody's line of sight that it distracts the defender to lose sight of their mark entirely.
Physical abilities alone, outside of the generation of miracles, they're all normal (and achievable). Hyuuga's streaky shooting, Takao's Hawk Eye, Kasamatsu's speed, Kiyoshi's right of postponement... They are all within reason
Watch a Japanese basketball game... There's a great disjoint on how basketball is played in Japan in real life and Japan in the anime world.
I think misdirection can be achieved by learning, because if you learn to constantly use silent steps and slide your feet for a moment, you'll eventually get the disappearing down. Since it's on a daily basis for me, it's like being an assassin or ninja being sneaky. That's my conclusion.
Highly possible to do all of these things, including the phantom pass. Though, your height and the strength in your legs would have to be incredible to pull of the jumps and continue running as they do. But all can be achieved, the phantom pass is more of an actual technique used in basketball.
Though you won't see something like that used often, coaches teach fakes more than they do misdirection. It requires no ball handling; well at least almost none. If you want to achieve misdirection, most is natural. The misdirection or 'phantom pass' used in Kuroko no Basuke, is most achieved naturally.
It's not something easily taught, I can naturally use it. It's as simple as a fake, maybe even easier. Stay invisible until you know you have a chance to score, call for a pass earlier to who you plan to pass to you. Once you arrive at the rim, almost like a phantom, the players not paying attention to you. Jump at the rim, since you are most likely to be blocked at a shot, put your hand up if above your shoulder and grab the ball, in that instant, shoot it back over your shoulder to an open teammate on the three point line or one with a defense who doesn't expect you to do so. If the ball is passed too low, lower your hand to the ball, the palm of your hand facing behind you. After you feel the ball in your hand, either grab and pass in that instant. Or you can hit it back down in an instant to your teammate, just like above, open or with a defender who doesn't expect it.
For jumping, it's just like in the anime, train the strength in your legs, hauling things back and forward on sand. Leg workouts of any kind, you'll be able to jump in no time. I've got an insane jump but I have to jump over and over, just like in the anime. Kagami's jumps only get higher. You start using more and more strength to put yourself into the air, realizing you need to use more strength. Your body responds to this and launches you higher.
The agility is possible, but very-very hard. The speed is the same as anything else, work your legs, train on getting faster, and the higher you raise your stamina, the faster you'll be able to run, as well as maintain the speed. Sorry for the 10 page long response. But it's not really easy to explain how all of the skills you mentioned can be obtained, as well as performed.