Question: 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.

Answer: 
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.