solaris 10 and windows shares

Solution 1:

2. yes (that's the purpose of Samba)
3. no. You will need to join the samba server to the domain for seamless authentication.

For 1. I believe the answer is maybe. Solaris does not have a in-kernel CIFS client to mount a CIFS share into the filesystem. However, the GUI (gnome) does have an integrated CIFS client, so whoever is sitting at the computer would be able to access the shares on Windows servers. Samba also have a command-like client that behaves like FTP to be able to fetch file. Depending on what you need, this may or may not be sufficient.

Solution 2:

1. yes
2. yes
3. may just be a matter of joining the samba to your AD, if you want to utilize existing security profiles and roles, but the Windows systems should be fine with no changes needed