Removing a question from a page
Any question can be removed in the page builder.
To do this:
In the preview of the page, click on the question to be removed.
The question will become highlighted, and the settings pane will open on the left hand side, populated with this question's settings.
In the settings pane, click Delete, and then confirm this in the popover that appears. The settings pane will close, and the preview will update to remove the deleted question.
Changes made to live forms affect data export
Changes made to the form structure can affect data exports. See Data Export: Changing Form Structure.