Also:
Thread@Subdivide[Most@list1, Rest@list1, div]
You can also use Range (which is Listable and threads over its arguments) instead of Subdivide.
Range[Most@list1, Rest@list1, Differences@list1/div]
{{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10},
{10, 8, 6, 4, 2, 0, -2, -4, -6, -8, -10, -12, -14, -16, -18, -20},
{-20, -(73/4), -(33/2), -(59/4), -13, -(45/4), -(19/2), -(31/4), -6, -(17/4), -(5/ 2), -(3/4), 1, 11/4, 9/2, 25/4, 8, 39/4, 23/2, 53/4, 15},
{15, 37/3, 29/3, 7, 13/3, 5/3, -1, -(11/3), -(19/3), -9, -(35/3), -(43/3), -17, -(59/3), -(67/ 3), -25},
{-25, -(41/2), -16, -(23/2), -7, -(5/2), 2, 13/2, 11, 31/ 2, 20}, {20, 10, 0, -10, -20, -30}}