Newbie Questions on Due-Date and date-format

Hi everybody!

I´m using RT 2.0.9.

In /opt/rt2/etc/
I inserted

    { Header => 'Due',
      TicketAttribute => 'DueAsString'

to display the due-date (search-page),
as roughly descibed in the FAQ.

Is this the right way?

Can I change the format to DD.MM.YYYY (the german format)?

Can I display overdue-tickets in red date?

What should I do to display the due-date on the home-page
( 25 highest priority tickets I own…)?

When creating a new ticket, what format is allowed in
the due-date field?

Can I enable the german format?