Hello @mdaruka,
If you wish to hide or not show certain old questions and only display new questions in your survey, you can achieve this by adding Display Logic to those questions with a condition set to False (Display Logic - True/False - False). Once applied, these questions will not be shown to customers, and you'll still be able to download old data from the 'Data & Analysis' tab.
Let me know if this helps.
I have a survey where the number of sunset questions is actually larger than the number of active questions, so I created a “graveyard” block to keep those questions and placed the block after the End of Survey object in my Survey Flow. (You could also use Branching with a condition that will never be met, like suggested above, to hide the graveyard block.) The data are still available in D&A and Reports.