If I delete my account will I be able to re-instate it at a later time?

Answer 1

Before you delete your account, download a GEDCOM or FamilyScript backup of your tree.  Lower left corner of the window has a download link.

When you create your new account you can then upload the backup copy of your tree.  You can do this by clicking on the My Account button (upper right of the window) then click on the create import new family button.