1. I would describe broadcast to someone by saying that when you put in the block broadcast hi , it will go to every other sprite in the project ,but every sprite won't receive the message hi , they will receive what you put on the previous blocks. 2.I would use the wait feature when somebody talks because I don't want 2 sprites talking at the same time so I would use the wait command.
3. I would use the broadcast feature when somebody is talking and the I would broadcast their message.