>    1. How can I change the colors of the NetBSD screen?
>    2. How can I change the resolution of the NetBSD screen?

Read the manual for iteconfig ('man iteconfig').


>    3. What do I need and how do I set it up to make my news and mails over
> NetBSD (nntp/pop3/smtp)?

Try to use NetBSD package system.  Read manual for pkg_add and similar
commands.  Try to fetch recompiled packages from NetBSD FTP server.


>    4. Is there anywhere a doc concerning the Amiga (except of the install
> notes)?
>    5. Is there a online doc for NetBSD? (I found in my local library only
> "UNIX System V" which doesn't cover all administrative topics at all :-(.

Start from http://www.netbsd.org/


>    6. Makes it sense to install X-Windows on a pure AGA machine?

If you don't have a gfx card - YES.  :)


>    7. How do I mount a amiga partition?

First, find out how NetBSD sees Amiga partitions.  Use
	disklabel <disk>
to find partitions marked as ADOS.
Then, mount the partition using
	mount -t ados -o ro /dev/<disk> <mount_point>
e.g.
	mount -t ados -o ro /dev/sd0e /mnt

	regards

		- Adam