Raising one arm above your head with an open hand.
The referee takes his arms, bends them inward and with fist over fist over fist rapidly moves them in a forward motion to signal traveling in the NBA
The players.
Yes
Foul and violation.
There are many like the shotclock violation, 8second rule
Travel
yes
Yes
There is no violation. It is the same as a pass
Yes. It is a walk
In basketball, if the player with the ball is moving (walking) without dribbling it is a violation called 'traveling'.
A Carry.