here are my comments to your issues (I am German, so I apologize in advance for mistakes ;-)
1. An offline client, allowing you to play campaigns against bots
I would appreciate because there is not WiFi everywhere, especially in Germany :-)
I really liked the campaign because the AI played specials tactics and you had to find a solution to beat it
2. A bot with a setting for different play styles
not so important for me, I want the strongest opponent possible, I want to get better..
3. A strong bot.
see my comment in 2; as strong as possible; btw: I think the bots play much better than e.g. 1 year ago; it´s fun to play with them
4. Options for timed games
not so important for me because I don´t play with unknown opponents
5. Options for undo settings
the present one is ok for me
6. Online mini-tournaments; the option to easily create one for you & your friends.
don´t need for now because I don´t have so many friends who play Dominion online
7. Option to invite specific players to your table
yes, would be cool; I am used to this option from other online games
8. More translations (to what language?)
German is sufficient for me
9. Better animations when cards are gained/bought/played/...
not so important; there is also the log to see transactions which were done
10. Better visualization of split piles, Archive/Crypt contents, Prince targets, ...
yes, this would be a great thing
10. Option to hide the log
nice, but not necessary
11. Android app (or just improved compatibility?)
I play on my Android tablet with browser; unfortunately not all browsers support fullscreen but I found one
12. iPhone app (or just improved compatibility?)
I don´t have one, so no issue for me
13. Downloadable game logs
not necessary for me
14. Improved moderation (dealing with chat abuse, slowplayers, ...)
since I don´t play with unknown player I have no feeling how big is the need for that
15. Tutorial on how to play Dominion
not necessary for me personally but perhaps for new players
16. Tutorial on how to play dominion online.
same as 15.
I really like the Dominion user interface and have fun playing this great game; some improvements would be great (see issue 10, first one
One correction: there is a spelling mistake in the German translation of the Empires card "Royal Blacksmith": correct would be "Königlicher Schmied" instead of "Könglicher Schmied"