Lots of little improvements are planned. Things like removing some of the excess info from tooltips to clean them up, then adding a "detailed tooltip" mode (default by holding Alt, but permanently toggled via an option) to add that info and more back on. Adding an actual main menu, save/load screens with multiple save slots. Things like that. The actual main game UI will likely stay very similar.
The map has a lot of potential improvements, though most of the more complex ones will likely be later.
A "Chance of success" sounds like it'd just be a yes or no, rather than a chance. Either you have the resources to complete it or you don't. It's a possibility though.
Custom combined actions, if they get added, will be highly controlled and much later in development (https://trello.com/c/VuYstcev)