IMO there is no problem with hex in ASCII: use a font where character's height is bigger than their width (standard ASCII VGA font has this property); and the six neighbors of the cell represented by (x,y) on screen are represented by (x±2,y), (x±1, y±1). (Half of the screen space remains unused.) Use 1,4,7,9,6,3 on numpad for movement. Maybe some small attunement is required, but it does not look stupid nor illogical for me. (The hex variant of hjkl is even more logical than the octagonal one.) Of course, there are problems if you want to have rectangular rooms, or whatever.
Also, you could consider using 1.5 for the multiplier rather than 1.4 (Rebel Star used 1.5). This allows easier tactical planning. Also note that POWDER has no diagonal movement.
I don't understand the comment about taking longer to move out of the flightpath of incoming missiles... obviously missile range should be also reduced in diagonal direction.