the only thing i can tell you, and i can easily admit to having seen this dozens of times, in various states of...alteredness (heh-heh) is that it is best to view it with people, preferably ones with some modicam of intelligence, and a whole lot of time to talk about it after words....it is literally quite open to interpretation.
back in the day, it was one my friends and i would debate endlessly, and never reach a consenus. back in the day, when i cared too much and had too much time on my hands, i actually read a book about the making of the film...and it's ambiguity was one of it's intentions. stanley wanted it to be enjoyed on a multitude of levels (which both p.o.'d a.c. clarke and had him admiring it at the same time, if i recall)...it's actually pretty darn complex and have gotten lost in trying to figure it out many a time.
if i tried to answer your ?'s, it'd be like this: 42, their clients, yes, sure, yup, uh-huh, alpha & omega, got me, evolution, sometimes, it doesn't.
i can only tell you one thing with certainty...and this would be the only rock solid answer you'll ever really get...and it is this :
if stanley kubrick answers your questions...run !!! hide !!!!