does the front line ever change position - i mean dynamically, - if there is an offensive, then does the winning side push the line back towards hte enemy? can air actions affect the success of ground activities?
The frontlines move in the game, typically on Jan 1 and July 1 of most years, to reflect the historic location for that stretch of the war. It's not dynamic in the sense you were mentioning, but works well for a war where the lines were pretty static. One airman would never effect the outcome of a battle so that won't happen in the game anymore than it would in real life. The main goal in the campaign is simply to stay alive and do your small part.