Two Q about Travelling, Double Dribble:

[mendi]

1) dribble end. you got pivot foot.
you raise the pivot foot. now you stand on the other foot.
(as i understand the rules. that ok to raise the pivot foot)
Now you must shot or pass, and its forbidden to bring down the pivot foot.
my questions are:
1.a) is there a time limit to stay standing on the other foot?
1.b) is there any travelling rule that say that its forbidden to jump on the second foot? (for exmple if you lose stability)

2) dribble end.
2.a)is it ok to throw the ball (gently and purposly) on the oponent body and recover it back after you did walk (ofcourse i mean that the oponent didnt touch the ball with his hands)?
2.b) is it ok to dirbble after you throw the ball on oponent body and recoverd it back?