Only during the initial 48 hour learning period to ensure the temperature reaches into the black band on the handset, then you will not need to move the control knob again. Subsequently changing the knob may require AIMS to relearn.
Yes, all cooking zones are affected, ovens and hotplates.
Yes, the AGA PCB will hold the latest programmed time, or you can simply switch to 'manual' mode to operate the AGA on normal temperature. If a replacement handset is needed, please telephone 0845 199 0045.