To customize and edit the questions in Spark manually, follow these steps:

1. Click on your profile located at the top right corner and select "Creator Dashboard".

2. On the left menu, click on "Spark".

3. Choose the Spark topic that you initiated.

4. Find the question you want to edit and click on it.

5. Replace the existing question with your own customized question.

6. Finally, click the "Save Changes" button to save your edited question.

By following these steps, you can personalize the questions in Spark according to your preferences.