AMP settings - Custom values & Off inquiry. -
1. The second one. If you have a 240Hz panel, everything will be automatically upconverted to 240Hz. No exceptions, no matter what. If you have 720p signal at 24, 30, or 60HZ, it gets bumped up to 240Hz if your panel is a 240Hz panel. Otherwise, you won't see what's being shown.
The AutoMotion Plus setting is different, in that it either provides additional processing (on any of the settings except OFF) or NO additional processing (when the setting IS "OFF").
2. I don't have a breakdown on the pre-sets, although they represent settings that are best for various inputs. Usually one of those settings will fit the bill. Otherwise, custom IS an option, but I don't have a reference point for those pre-sets.
3. 0 would be the lowest setting, and 9 would be the highest setting. Only the Preset OFF is "Off".