Earlier I posted a question which is flagged as it is inappropriate and I could not delete it due to answered. Now I changed both the title and content see link below, my question is since the new question is entirely different from the original flagged question is this recycling of question allowed? The comments and answer posted for original question is irrelevant to the new question is there any advise what to do with them?
No, this sort of recycling is not allowed. In general, any edit which completely changes the essential nature of a question is not allowed, because - as you noticed - it invalidates existing answers, and it also messes things up for people who may have bookmarked the question to come back to it later, and so on. If you want to completely change a question, just post a new question.
Editing an answer to change it completely is not so bad, but only if you are the one who originally posted the answer, and it's rather discourteous if someone else's answer references yours. So, let's say, try not to do that very much.
Any time an edit invalidates comments, that's fine. Just flag one of the comments as obsolete.
In this case you should also roll back the edit that completely changed your question.