Yes you can edit the style.css file to edit both these things.
Line 451
.navbar-default
Delete this
box-shadow: 0 3px 6px 0 rgba(0, 0, 0, 0.2)
As for the lines on the titles,
Line 125 and 113
h2.bigtitle:after
and h2.bigtitle:before
Delete both of those.
I hope this helps.
To edit the style.css go to Appearance > Editor and select style.css