by dedindahed
1) Just the adventure2) You can move through activated areas without penalty, you just can't move out of an activated area if you started inside.
3) There is a battle if you move into an empty enemy stronghold. You can draw battle cards, though mostly they will have no effect, but necromancers may be able to raise re-animates and the siege tower use it's strength bonus etc.
Then standing strength is counted and you need to have more units than the current defense of the stronghold to capture it.
Moving into an enemy home region that is empty also counts as a battle, and you may draw cards if you have any units that would benefit.