Print server and Domain Controller

I have two questions:

1. We are making new print server and I wanted to know if we set-up new Print server and give the same hostname an IP address to it as was given to the currently live server. IN that case, do we have to re-configure Printer on user’s machine or not?

2. My second question is I have just put one of the server in workgroup and then re-joined to domain, but after re-joining it is not showing in Active directoty, however I can see in DNS forward look-up zone?

regards,
RAvi bhanot