Taking your first question, the way I do this on my own private network
is:
smbmount //host/share /mountpoint -o username=user%pass,uid=nnn,gid=nnn
- for uid=nnn, nnn is the user-number the shared files should have when
I access them
- you can guess what gid=nnn does
- Using the user%pass option is a security hole if someone else can do
a 'ps' command on that host. Leave it off and enter it separately
then.

If this does not work then you need to start looking at error messages
and the logs on the server for rejected access attempts.
Btw, you say that it does not work but you do not say what form this
'not working' takes.

I'll pass on your second question because I have never felt the need to
do this and because it was non-trivial last time I looked. I use SuSE
and know that they have some mechanism to make this work, but another
distribution may have a different method or may not have addressed the
problem at all. Simply mounting the share via /etc/fstab will probably
not work because networking is not up when fstab is processed (that
applies to nfs as well, but there is a standard mechanism for fixing
that problem). Some form of automounting may work but I have never
investigated it.

Thanks you Vald

I can mount it with a certain Userid , but all files written into the
share will have the same uid and gid , If the share is used by many
people with rw access , I think it cannot be implemented .