Hello! Just started playing beta 2 a few days ago and have a few minor interface and usability issues that I thought worth mentioning and here's the first I have time to write down
It concerns moving out units from a city. Small niggles here but being quite environmentally damaged from studying and working with interaction design they stand out to me 
- If one or more units have just been moved out of the city, make them selected. If a unit just got moved out of a town it's most likely that the next thing the player wants to do is give it further move orders. As it is today, the town remains selected.
- The buttons for moving a unit out are really tiny. I first thought them decorative, part of the circle around the unit icon
The hit area for them is so small it doesn't appear that they are buttons at all, espcially since few other buttons in the UI are anywhere close to that tiny size. Make them larger or redo the interaction there. Maybe either remove it since it can be done two other ways, or allow for some other type of larger button (like a separate eject button that moves out those you have selected perhaps).
- Promote the right-click functionality by highlighting the squares outside a town once one or more units are clicked. That way the player gets some kind of hint that something can be done here on the map once a unit has been selected.
- The Stationed Units window can't handle multiple selections. In the city screen you can shift-click to select several units which is great when you want to move out a large army. The Stationed Units window doesn't support that interaction however, it should support shift-clicking too. There is also nothing that indicates that it is indeed possible to do multiple selections, even though I might imagine that to be a quite common thing to do for both experts and novices. I could even imagine skipping the shift modifier altogether in the Stationed Units window and instead making each click simply a toggle for selection of that unit, with the border around the icon clearly indicating which are selected. You can't do that in the regular city screen since you need to be able to click each unit and check their stats window and then you need to have only one selected at a time as default. The Stationed Units window is more of a modal dialog however, so shift-clicking there ought to work better. If the player then wants to move an individual unit out of town they click it in the town screen, if they want to move several out they can then either shift-click in the town screen or first click the shield and then in the Stationed Units dialog click this, this and that unit and then the button to move them.
- Come to think of it... there are three different ways of moving a unit out of a city. The tiny button, selecting them and right-clicking outside or using Stationed Units. Redundancy can be fine but is it really necessary to have three ways of doing one simple thing?
It's ok, but does lead to more icons and windows. Perhaps the functionality of the Stationed Units window can be incorporated into the regular town info, or the town info tiny buttons could be removed and the right-click functionality instead made much clearer.
Sorry if I'm rambling way too long about minor niggles 