To edit a question, select it from the middle column by clicking on it. If you want to re-arrange the order of the questions instead, just click and drag the input where you want it.
On the right column , the settings panel for the selected question is activated when clicking on a question. Perform you edits here.
The formbuilder validates questions automatically most of the time, just by interacting with it.
If you would like to force a validation on the selected question, click the validate button on the top right of the settings panel:
A valid question can be copied to the bottom of your question list by clicking on the copy button:
A question can be deleted clicking on the delete button:
If it happens you delete a question by mistake, do not worry. Just do NOT save, but click on the UNDO button instead:
All the questions for a form can be deleted at once, without deleting the enclosing form.
Select the form and click on the "Delete all questions" button in its context menu.