What if there was a way to see in Dwarf Fortress mode how likely an area was to caving in?
Basically, when you go into this view you get an overlay of colored X's (sort of like how you can see rooms) depending on how far away a floor tile is from a rock wall, where ever you have dug out or planned to dig. Green would be safe, yellow would be caution, and red would be a cave-in, which turns all nearby tiles in a 7x7 block (the original red tile is the center) red as well.
So for example, a single, double, or triple wide hallway would be Green. Four, five, and six tiles wide would be Yellow, and as soon as one tile turns Red, a 7x7 block of tiles centered on the original red tile will turn red as well.
And if you really want to, the game could predict where you would have to dig in order to cause a cave-in; imagine you dug a 7x7 room, but left one of the corner rocks alone. The 7x7 "-1" room would fail to collapse because of that one rock, and this vision overlay would display a Red X where that rock is, because the removal of that rock would cause a cave-in.
As usual, none of this is necessary. It's just something i thought up that would aid the player in planing out his fortress, and more easilly avoid annoying cave-ins (unless of course causing a cave in was his objective; there's no point in stopping that) and thus improve gameplay for everyone.