1 - auto collect would be great
2 - more land or better yet, I like the idea of a second island (like the arctic island on the iPhone) to house dragons to just keep. There's a whole thread about it
3 - at least one gold producing dragon you can get from essence, but better gold producing dragons sales
4 - confirmation button before buying anything with gold (I accidentally collected the last few shields needed for the dragon you get from battling - it was only 10 gold or so so I didn't put a ticket in but a bit annoying).
5 - Do something about the tournaments. As a level 200 player with multiple level 15 dragons I shouldn't be stuck on a dragon for over a day! (GUH!)