A lot of the important buildings are linked from the resources "Ribbon". For instance, clicking on mana will open a pop-up with options to upgrade the mage tower / cast spells. I love this BTW - great to click on a resource you want to use and see what ways it can be used.
In a similar vein, and if my memory of this type of thing is anyway consistent - very easy to implement a new one, is it possible to add a similar link so when you click on "beer" you not only get the option to BREW beer but also to go on a quest.
And again, when you click on a sword, you not only get a link to the BLACKSMITH but a link to the Barracks (recruit troops link). Same thing for spears and bows.
Horses as a resource could be linked to the Consulate and Barracks as they are key resources for both those unit types as would be saddles.

Also - I know it's been said before, but really annoying how you have to click into quests twice to send resources / diplos to perform the task and then have to either use the Browser back button or click in via the town again to return to the Tavern.