Achieve an erection spontaneously in a short period of time(without mental arousal or physical contact) can be done, it is hormones that cause this and when being a teenager, guys will sometimes get hard, for no reason at all but this goes away after puberty is done with, about age 20.
Have an orgasm without ejaculating, this can be done most easily with the 'Stop and Go' style of masterbating and you can have an orgasm without ejaculating, and sometimes I can ejaculate and still keep on going when I get too close to being completely over the edge.
The yoga master ejaculation trick, lol is this mean self-suck or anything with bending to get in unusual positions because I really am not sure about which one you mean, but both are done by stretching and sucking yourself or leaning back as far as you can and then just fucking the bed.
Ejaculate on cue (seems unlikely, but who knows?), it is possible and men in the porn industry, with directors that is...do have to learn to cum on cue or close enough to it so that the camera angle and scene ends just as the script says. You wouldn't exactly want to cum too early when she gives a bj or you fuck her breasts, because these are so easy to see when they cum they'll have to redo the scene, and though it sounds like a good job, but having to do this with some girl who you don't even like or think is attractive is a disadvantage, and they get that quiet a bit for what the work promises. XD
Control the valve that makes you unable to urinate with a full-on erection, sry this is involuntary and is automatically done when a guy gets a hard on, but when he starts to get soft he can pee again while he is still half hard.
I think that basically covers it, any more questions?