Techical/APTI violation

[OldCoachNewRef]

IAABO test tonight. Still have a couple of questions:

1. Technical foul. Who can shoot? Can someone come off the bench, shoot the T's and then go back to the bench? In other words, does there have to be a substitution made?

2. Pregame dunk on team B. Team A shoots the T. A1 gets ball for throw in. AP now points to team B. A1 violates by stepping 4 ft to the right. Usually on APTI the team that violates loses the ball AND the arrow. What happens to arrow here? Team B already has arrow. Is the first throw in considered an APTI (alternating possession throw in)?

Thanks in advance!