This will be an ongoing list as things occur to me over time. I believe this reflects the views of MANY advanced players. This list is NOT in any particular order of importance. Just as things come to mind. I encourage others to write comments and add to thois list as they see fit.
1. We have recently seen color filters added to the breeding scrollbar interface. I would LOVE to see these aded to the Battle/Arena interface. Sometimes I know exactly what type of dragon I want to battle with but with 600+ dragons it is very time consuming to scroll to find it. The color filters wou;ld make this MUCH more efficient.
2. In Breeding there is a new Rebreed button. We need a Replant button on farms. I usually plant Rushrooms, sometimes Upgrapes or Diamondates. With a Replant button it would save MANY many clicks over the course of time.
3. We desperately need NEW additional gemstone dragons added to the Crafting list. I have long ago completed ALL of the available gemstone dragons (several in duplicate).
4. The ONLY quest which is remotely useful to me anymore is the Food quest (Magical something or another). Fire/Coin quest used to yield gold. No longer so it is just a waste. I have expanded ALL of my available land so Mapping the Island is irelevant. I don't need gems anymore, The Comet quest might be relevant but I have NEVER secured any materials despite several attempts.
5. We need more efficient farms and/or food types (perhaps add a new set of uber expensive but highly productive and efficient food choices).
6. It would be NICE to have a dragon album similar to that in the Fantasy Forest game.
7. On the Evolution Temple it would be nice to have a status popup which tells us what dragon is evolving and the current level of the dragon. Oftentimes I completely forget who is being evolved. This could be invoked either by hovering over the Temple or clicking on the icon.
8. In Bingo perhaps add another tier above Gold. Maybe Platinum? I have been in Gold league since advancing up from Tinder/Bronze/Stone/Silver. Still only get between 2-5 Tickets -It will take FOREVER to get that Gold Type dragon-.
9. Maybe back off a bit on the requirements for the Mining Dragons. 275-300 is A LOT of parts to mine.
10. Fix the horrible CRASHING issues!!!
EDIT: Added these:
11. There are decorative objects (Eternal Flame (red), Flower Egg (green), Sunshine Temple (yellow), Planetary Tower (purple),Pantheon Pool (blue) and Garden of Light (white) which increase the coin capacity for the various color habitats upon obtaining 10 epic dragons of the specified color.
A logical addition would be similar objects for Black, Pink and Gemstone dragons (maybe for Champion and Diamond type too). I don't really care about coins at this point but would love to have a decoration appropriate to these types (I have my BIG island designed with a bunch(9) of 3x3 blocks with the temple in the center and 8 habitats of corresponding color surrounding them. Impressive design but I lack the appropriate gemstone/pink/black objects.
12. Dealing with storage is a pain. When NEW stuff goes in via events like World Event they should end up at the very TOP. It is sometimes painful trying to find new stuff (it looks like the new collector 'Shimmerstone' behaved in that manner. Previous occasions this has not been the case). Also a function to be able to archive OLD material from prior battle and mining dragons in addition to a subfolder for duplicate dragon eggs and less desirable decor.
13. PLEASE add a Confirmation dialog for ALL gold expenditures! It is so EASY to end up accidently spending gold for STUPID crap. I just accidently spent 20 gold on my girlfriends account for 5200 food. No way to cancel that accidental tap. She won't be happy when she notices the gold deficiency.