I have played H&H for a while, and at the beginning the UI was a little bit weird for me, but since I'am old enough to remember games before th PC era, I got used to it.
This game is supposed (as I belive) to be a step forward - 3d graphics etc. ..If so - maybe you could make the interface a bit more user friendly? Let's take skills for example - It shouldn't be that hard to represent them as a tree instead of a list - would be much easyer to see which ones are required for others. And maybe some tooltips which will show what actually you get when you obtain them, instead of (or in addition to) those fancy, mysterious descriptions.
At the moment, when I play - I am constantly swaping between the Wiki in a browser and the game. In fact - I read more than I play. The game has some very complex mechanisms - that's ok ..very OK even - but the game itself does not explain them ..I have to constantly look for answers on the Wiki (which is btw not competly up-to-date) or on the forum.
There are also many other litlle things ( like maybe a summary of the stats you get from sloted items? ) that would need improvement but I will not talk about them becouse the post would be just to long - what I am trying to say is - take a look at the UI from a prespective of someone new to the game.
Also alot of nice features are added by custom clients - but is that the answer? - should everyone use them instead of the original ? (like it was in H&H).
I know you overhauled the interface at least once - its better than it was, but its just not good enough.
So if you are planning to attract more players to the game, I would strongly suggest to make the UI more friendly to newbies.