I suggest that you get the CVS version of groff...
> 2. Foreign languages: How can I load different
> hyphenation patterns, if they exist?
This has been answered already. German support has been integrated
into the CVS version.
> 3. UTF‐8 support: It seems that with "‐T utf8", groff
> spits out utf‐8 but only accepts latin‐1 as input. Is
> there a way to make groff accept utf‐8 as input as
> well?
Again, with the CVS version, just use option `-k' of groff (and read
the `preconv' man page).
> Will there be support for utf‐8 fonts in PS output?
This isn't necessary since groff relies on glyph names; Bruno haible
has improved TTY output for Unicode.
Werner