As far as I understand, a line break (Shift-Return) should do nothing but break
the line, unlike a paragraph break (Return), which also ends the paragraph.
However, when I press Shift-Return within a justified paragraph (which is useful
in some cases to force certain words or characters to be wrapped into the next
line), the line that is ended by the break is no longer justified, but
left-aligned as if it was the last line of the paragraph. I think it should
rather work like in MS Word, where the line remains justified (i.e. the words
remaining in the line are stretched a bit more so they fill the entire line again).

One example for a text where a line break within a paragraph is required:

  The configuration file can be found under /
  etc/mail/exim.conf.

This is what it should look like:

  The configuration file can be found under 
  /etc/mail/exim.conf.

OO Writer treats the "/" character as a word separator, causing it to wrap the
path name "/etc/mail/exim.conf", so the first "/" stays in the previous line,
which is of course unacceptable. So the solution would normally be to enter a
Shift-Return before the first "/" to force it into the next line. But in OO
Writer, this will cause the first line to be left-aligned, breaking the
appearance of the paragraph (if it's justified).

I think this issue can be fixed rather easily.