it looks like you deleted your sketch you used to make your extrude. (that's why you have errors in your timeline). Then you preceded to do a bunch of moves and offset faces to effect the shape. basically, a cut and paste, photo shop type of approach.
this approach doesn't work great with parametric modelers.
a couple of suggestions.
-don't delete any sketches you use to make something.
-do delete empty sketches and un-used commands as you go so they don't clutter up your time line.
-NEVER use move to move a body.
if you had kept the sketch, all you would have had to do is edit the sketch to change your shape. here's a screen cast of what I mean.
