Since feeding got less expensive, it would be nice to have a "Feed to 20" and/or "Feed to 30" or even "Feed to 40" button on each dragon, so I don't have to hit Feed 80 times for 20, 120 times for 30, or 160 times for 40.

Yes!!! I spend about one-eighth of my Dragon City time just sitting there, tapping the Feed button. I would love for this feature to be implemented in the game!

And this can maybe work with other button-pressing tasks like crafting crystals in the ancient world... There could be a button that says Craft x5 or Craft x10 or even Craft enough to Evolve (or summon)