Pitch Snap: When this switch is on, all the edited points and sounds are snapped to the closest pitch defined by the pitch scale. This pitch scale can be edited View > Pitch Scale. Works with all tools.
Time Snap: When this switch is on, all the edited points and sounds are snapped to the closest bar, beat or subdivision of beat defined by the time scale. This time scale can be edited with the View > Time Scale menu. Works with all tools.
Level: lets you define the level at which new sounds are created. Use the combo box to set a level between 1 and 9. Note that changing the value in this combo box has no effect on the selected sounds: only newly created sounds are affected. Use Edit > Set Level... to set the level of the currently selected sounds.
Note that you can set the level much more precisely with the Edit > Set Level... action, including non-integer values and values above 9 or below 1.