Hello Ricard,
you can use Flight modes in your futaba radio.
One flight mode will be dedicated for the Rescue mode - this flight mode will be activated by the momentary switch. There you can also define flat throttle curve when it is active. There you can also program value for Bank Switching so that it will always switch to a desired Bank (with Rescue programmed).
Other flight mode can by for flying, another one for stabilisation.
In this way you can use all 3 banks and have it as you wish.
Regarding your last question - please check this page:
http://aero-man.spirit-system.com/index ... on_vs_GyroBasically Head-Lock is active always when Stabilisation is active or Inactive.
Only when Function is set to Disabled, you can get Normal (Rate) mode which is different from Head-Lock.