1. I usually do all these activities in the classroom but they are used depending the class situation, if its a kids classroom before starting the lecture i ask them a question about a news and i make myself the centre of attention by using " show and tell" and " conversation". In the teenage classes i usually start the lecture by "debating" between groups of students or doing activities like " chatting" in pairs and then having their " role play" by standing up and describing their pairs ideas.
2. These issues are very normal in almost every class. As the students make mistakes i give them time to rethink and correct their mistakes or in the end of the lecture i correct their mistakes to not to ruin their motivation. If some students aren't interested in the topic they probably won't participate which is teacher's job to engage them to the lecture by using different tricks. Some students talk in their mothers language and the teacher should give them time to get used to the new language they learn but that may affect their progress.
3. I suppose the lesson plan for excercise 5 is perfect but i don't think the timing would be exactly the same because the students may make a lot of noise which would interrupt the teacher. But if they are good as mentioned i would love to teach a class like that. The methods in the excercise 6 are good, but i think if the teacher changes ways for students to talk like: working individually, in pairs and with groups would make them more engaged to the lecture.