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