6. Is it possible to programme a VSI, so that the 'lock' function is disabled?

Yes, but you must have a 'B' level hand-held or PC programmer to access this parameter. Depressing & holding the 'on/off' button, once the unit has been powered-up will normally initialise the locking sequence on any VSI. The joystick is then moved forward & then backward to 'lock the' controller. This operation is performed purely to prevent unauthorized use but occasionally an end user may ask for this feature to be switched off. If you do not have access to a 'B' level programmer, you can return the unit to our Customer Services Department, where they will be happy to effect the change for you.