Harry Mbang wrote:

1)Can not open exclude file /usr/local/lib/Amanda/exclude/gtar ...

So you have a dumptype that says there is an exclude file there.
Alternative solutions:
 - remove the directive that you have your exclude file
 - add the directive "optional" to the exclude statement
   so that amanda doesn't complain when the file is not there
 - create the file (may be zero length, or filled with real
   exclude patterns)
And btw, the file should be on the CLIENT, each client that
you backup with that dumptype.

2)Can not read/write /etc/amandates ...

as root: touch /etc/amandates; chown amanda /etc/amandates

3) Cannot read/write /usr/local/var/Amanda/gnutar-lists/ ...

As amanda (or as root, and "chown amanda ... " afterwards:
  mkdir /usr/local/var/Amanda/gnutar-lists