Well you can use some of the guides here, to make things more easier to find. (You probably have already seen the Pokemon Location Guide but it is still not updated to ep16 so feel free to ask questions regarding mons not available in the guide.
Fly towards Grand Hall and talk to Ame that's where to start the Devon Quest and after completing that quest, you can then again go to the upper floors of the Devon Building to get the Devon scope.
TM X5 WaterfallGiven, regardless of answer to Blake, in Ametrine, if "Yes" from Blake, if "No" from Aster after defeating him just before reaching the Ametrine Mountain Peak
You should use this next time:
Smeargle has the move "Sketch" which copies the last move used in battle, so if the last move used was the one you were looking for then you can then use sketch and breed that smeargle.
Don't know about the energy root but maybe it's beside the Obsidia Dept. Store, White herb is:
Herbs (White, Mental, Power Herb)
Dpt. Store 5th Floor for 1000
And the ring is in the sunken villages in the lake and you get the spoink's orb when you get the ring to the lady.
EDIT: In Madame Meganium's Magic Medicine Market you can get the white herb and energy root.