Flags for improving scrolling and battery life???

As Ryan mentioned, the most effective one is that
"Turn off caching of streaming media to disk."
but you'd have to use Canary channel instead of Dev.

leave the rest at default values to prevent instability.

for scrolling, go to edge:flags and type in "scroll"
then try each one of them Yourself and keep the one that you like enabled and revert the other ones back to their default values. because you're using Touch screens, and i assume tablet?

smooth scrolling for example doesn't show any noticeable difference, maybe because it's enabled by default. and since the majority of flags don't tell you whether their default value is enabled or disabled, you just have to try it yourself on your Touch screen device.
🙂