1 - Yes, I'm pretty sure Grafpup 2 uses a genuine /home directory
2 - In general (almost all the time) packages for Puppy will work in Grafpup, although there are probably a few that won't (most likely if they were compiled for a Puppy 3 or 4 version). Try and see. To look in the Grafpup repository go to grafpup.org, click on downloads, then packages, then 2.0. Or there is a package manager in the menu in Grafpup.
3 - I haven't checked if they are in the Grafpup repository, but I think I vaguely recall seeing TightVNC around somewher, and there are a few SAMBA packages around - there is an old dotpup that is huge and has all the documentation and everything. I think everything you need except smbspool (available on the Puppy forum somewhere) is included with the (relatively lightweight) Muppy-smb package. I think there should also be SAMBA server packages in the Puppy 3, 4 and probably 2 package repositories. I suspect any of these would work - but I've only tried a couple of them and only in Grafpup 104 (the large dotpup worked well but I can't get smbd and nmbd from Muppy-smb to stop). In older versions of Puppy there was a "Samba" package from the package installer that was actually just a Samba client, and it is possible that is the case in Grafpup 2.