Thrown-in
If you are ready to take a thrown-in, the player taking the throwing can play the ball as soon as they are in a position without waiting, even if not everyone is on court.
Video - Throw-Ins

Toss Up Removal
If a simultaneous infringement occurs the umpire awards possession to the team that was last in possession of the ball, where the ball was when play was stopped. Any player from that team may take the ball for the restart of play. It does not have to be the player who actually had the ball last.
Video - Toss Up Removal

For both of these rule updates, please scroll down to find the Fact Sheets.