You are correct, you want to style your paragraph using css. How much you style is up to debate...
Use search/replace to remove them!
search:<p>& # 160;</p>
replace: (nothing)
or
search:<p> </p>
replace: (nothing)
It should only take a few seconds. Before doing that though, I would check all of your non-chapter files...back matter, ToC, Also From, etc. ...to make sure they don't have those blank lines that you actually want to keep.
Cheers,