In A, the subs can be made anytime -- as said, a sub can enter and take either or both technical free throw, so a substitution needs to be legal there.

In B, check with your local authority. Personally, I hate this practice (one day there will be a brawl that comes from this nonsense), but we have no rule against it here, so I just make sure to be vigilant when the other team returns.

I have more interesting questions, like why the teams always run drills into the one spot on the sideline where I want to stand during warmups?

I appreciate the responses. To be more specific: If no one is entering to shoot the throw(s), and there are some players that had properly reported prior to the tech, when should they be beckoned? Before the 1st? Between throws? After the 2nd? We discussed the other night and had different answers amongst my crew... Just want to do it right, in case anything silly happened during the throws, want to have the correct players on the floor; I don't know if it makes sense to bring them in between throws, since the ball will be dead after the second throw? Anyone know definitively? Thanks for the help!

Common practice for me, I usually wait until the final free-throw..

You can bring them in at any time. If one of the subs is for the player who got the T, I get the sub(s) in ASAP to get the problem off the floor.

If not, then I usually wait.

By rule, the requirements for a sub are met.
1. Dead ball
2. Clock stopped.

The exceptions built into the rules don't apply here:
1. reporting after warning horn of timeout or intermission.
2. PF FTs with more shots to follow.

No need to infer anything from the ability to bring a sub in to shoot TF FTs. You just need to realize when the exceptions apply and when they don't.

As has been stated with the full court drills: there's no NFHS rule against it. Your state/conference/governing body may rule otherwise, however.

I seem to remember something about this in Oregon a few years ago, but I think it applied more to introductions than warm-ups when one team was clear off the floor.

I know that that year I had one game, rivalry, where home was introducing one girl from each team alternating (weird sentence, oh well). They were crowding into the center circle for some reason. Girls from one team on one side, other team on the other. One girl reached across the division line and goosed an opponent pretty significantly. Partner and I, standing at half-court saw it perfectly. I started to march out and whack her, but partner grabbed my arm and stopped me. He looked at the coach, who screamed at the girl, problem solved. Both that girl and I learned something that day.

I hear you!
 

I have more interesting questions, like why the teams always run drills into the one spot on the sideline where I want to stand during warmups?

I love it, in last weeks game I told my partner the same thing!:) I've felt like a target lately.