Resumption of play following a time out during free throws

[Jurassic Referee]

Originally posted by truerookie

1. Are you required to blow your whistle to make the ball live again?

Blowing the whistle never makes the ball live.

The only reference that you need is NFHS rule 6-1-2.
The ball becomes live when:
(a) on a jump ball, the tossed ball leaves the referee's hand(s).
(b) on a throw-in, it is at the disposal of the thrower.
(c) On a free throw, it is at the disposal of the free thrower.

That's it. Don't overthink these things and make it hard for yourself.