Behaviors are tied to layouts because then you can change behaviors just by switching layouts. For example, you might want auto-scrolling to start upon song selection when performing, but not when rehearsing. So you can set up different layouts for each. If layout actions were moved up from the layout level, they would still be at the device level, because you might want to use different devices for different purposes. For example, you might want to send MIDI from one device and use another device to run an external display. So you would still have to do some setup when adding a new device.
Anyway, if you're moving between devices with different screen resolutions, you have a few options:
1) Manually compare your layout settings and enter any settings you want on the new device.
2) Set your layouts to Scalable, and they will appear on all your devices, but might be letterboxed or pillarboxed on different screens.
3) On the new device, make a copy of the layout from the old device. This creates a version of that layout sized for the new screen, and carries over the layout actions and other settings. You can then edit the visual portion to utilize the new screen size.
4) In the next feature release, there will be an option to resize layouts for the current device. This will be kind of a combination of options 2 and 3: it will carry over layout actions and other settings, and will scale the visual portion automatically, and then you can tweak the visual portion further if needed.