No, that's definitely not ok to ask for some time after each question. If you try to link at the whole interview situation as a discussion between consultant (you) and client (interviewer), it's just not how you would discuss with a client in reality.
Taking time for the initial structure (or at least asking for it) is definitely ok. For any later, more detailed question throughout your case interview you can just pause a couple of seconds to structure your thoughts, but not really take more than 5 to max. 10 seconds (which is still a natural communication situation).
However, if you feel that there is a really big additional question lateron in the case, and taking some time would significantly improve your answer - then you can at least ask the interviewer if you can have a moment to structure your thoughts. Don't expect that you will be granted this additional time too often - just ask for it but don't expect it.
Hope that helps!