Here are my general tips for case communication.
Take a few seconds - gather your thoughts. Perhaps right them down. Take a quick breather to better formulate and then articulate your thoughts
- Pause before speaking to gather your thoughts - the time may feel like forever for you, but it's not nearly as long as you think. Leverage filler sentences such as "that's and interesting point" to buy some time if needed.
- Frame your answer - Generally, MBBers say "There are 3 parts to this". Then, they highlight in 1 sentence each of the 2-4 points
- Iterate through each point - After framing how you're going to answer the question, then answer it by diving into each "part" in the order you summarized each.
Use signposting - Always preface what you will be saying. For example, when brainstorming you can say "I'm thinking about this in three main ways: A, B, and C. Within A we can look at..."
Be objective-driven - Everything you say needs to clearly articulate why you're doing what you're doing (i.e. how does it help you answer the objective)
Practice with a coach - Other PrepLounger are fantastic practice but they are generally too nice! you need a coach who will really hit back and work with you to improve your answers.
Now, in terms of your questions:
- Can we really ask for time to structure our thoughts throughout the case when asked a question? How to know when it is authorized?
Here's the rule: If you can answer the question in an organized, “good” way without taking time, then don't. If you need time to give a good answer, take it.
- How many ideas to communicate when answering a brainstorming question? Should we say only the most realistic ones or all of them? In what order?
It totally depends on the question! You need to gauge the complexity/size of the question. Importantly, make sure you structure/group them where valid. Order them in the order that makes sense (i.e. if there's a flow/process, or the biggest first, or the most likely first)
- What time it is best to allocate to communicate the initial structure and the answer to a brainstorming question?
Please stop overcomplicating this! You should take the time needed to answer the question well. And not a second longer. Go as fast as you can while still being structured, objective-ness, concise, and precise.