I'm pretty sure that OM makes all ships enemies; there are no neutrals. Also there is no chart that shows who sides with whom when, so it's really okay. One of the many things that needs fixing.
As for German voices, if you want stock SH3-style voices try this mod:
http://www.subsim.com/radioroom/down...o=file&id=1157
And if you want the voices and sounds from
Das Boot, go here:
http://www.subsim.com/radioroom/down...o=file&id=1083
And a little add-on that goes with DBSM:
http://www.subsim.com/radioroom/down...o=file&id=1529