There are three features I really miss that much in game, that I might consider this a bug:
1. When you complete a research you get this message pop-up showing you, what you get out of this research. When you move your mouse over a new unlocked building you get a nice mouseover help what this new building is doing. That's nicely dome. However you don't get those mouseovers for new unlocked spells, and I am really missing that. I am not sure if you get mouseover for unlocked weapons, armors and the other stuff. In my oppinion you should get detailed mouseover information for everything in the research message.
2. When you create a new leader and choose the kingdom/imperium for him, you get little information about the factions benefits: You don't get informations about unique buildings, equipment, abilities (like the sneak ability Umber has for example). Instead you have to leave leader creation and have a look at an allready finished leader to get an idea about that. That's very much inconvenient.
3. If I am right, you can only build peers, docks and so on in cities founded next to river. But why can't you build this buildings in a city found next to the sea? That doesn't make much sense to me. Cities found next to the sea are usually a little bit weak (especially little production) and therefor it would help very much, if you could at least build those buildings there.