I don't see this option anywhere and manually dragging them around is getting a bit annoying. Let me know if there is something I'm missing please.
When in Project View (only), just hit the "s" key to sort by Due Date; to sort the Tasks in the current Project View by Priority, hit the "p" key.
Please understand that this sort will only persist until you add a new task, at which time you'll need to manually resort the Project List.
Any filtered view (Today, 7 day, etc) is will automatically be sorted first by Due Date (and Time, if applicable), and then by Priority.