To move a task up or down, right or left (to change the inclusion level in the tree-like structure), click at the task and use the Ctrl+Arrow up/down/right/left hot key combinations. To move a task to the top of the list — use Ctrl+Shift+Arrow up hot key combination, to move it to the bottom of the list — Ctrl+Shift+Arrow down hot key combination. You can also use the context menu of the task: right-click at the task, in the appeared menu choose More — Move and the move point you need.
This way you can also edit projects in the Navigator, Tags in the menu Database — Tags, and contacts in the menu — Contacts.