Proportional editing

Support Modeling
1

i am trying to do a stair case post i cant seam to get all the edges rounded[
http://pasteall.org/pic/c2eb758b5808d7aff658843e4bf6d3a3]

http://pasteall.org/blend/index.php?id=51696

2

what part of the stair case is this ?

3

the top of the square