Advice on moving from workgroup to domain for very small network

Question

Hello all,
I work for a small company and inherited the part time IT/Operations position and I want to understand the impact of changing from workgroup to domain.  I understand the process and I have set up small test domains before but I want to be certain I
understand this so I figured I better ask the pros.
The setup:
1 Desktop class system, recent i5 quad, 16GB RAM, 1TB HD with Server 2008 R2.  Current roles are File Sharing and WSUS. 
3 Desktops running Win 7 Home
1 Desktop with win 7 Pro
1 Laptop with Vista Home
1 Laptop with Win 7
1 Laptop with Win 8 Pro
I have configured all devices to uses the WSUS for updates as they wanted these managed and this seems to be the easiest way.
Right now all users have an account on the server that is used to map to their shares.  I know that the home versions cannot join to a domain and with this small of a network I don't want to join any device to a domain as we have only one server and
it would not be reasonable to add more servers.
The thing is they want to setup local sharing of calendars and contacts, etc.  I have 2010 exchange server and it is required to be on a domain.
The Questions:
Can the domain still "act" as a workgroup and users still connect to the shares and exchange without being joined to the domain?  What is the impact on performance for this server?  Will the home version users still be able to connect to
the shares (I assume yes) and to the exchange through outlook?  Is there a better way to achieve the workgroup features of exchange without using exchange and not subscribing to Office 365?  We do not have an internet domain name for this business.
Does this matter for setting up a domain?
Anything you can think of that I should consider please feel free.
Thank you all for your advice.

Answer 1

Hi Paul,
You are very welcome, I am very glad that my suggestions helped.
For your first question, in a domain, the Domain Controller clearly has much more tasks to perform than a work group server, while it also has more management options for an administrator to better control his/her client machines.
In addition, domain acts as a central management solution will reduce the work of the administrator. For an example, under workgroup mode, if we have multiple servers which have shared resources, we need to create the same user
accounts on each of them, while in a domain, we only need to create accounts once on the DC, then all the accounts can be recognized across the whole domain, no matter how many servers and client machines are within it.
For the second question, yes, single lable domain name is not recommended, but it is allowed. Single lable domains are supported in
Exchange Server 2007 Service Pack 1 (SP1) and Exchange 2010, while single label DNS name resolution is also possible.
However, there are other Microsoft and third-party products which don’t support
single lable domains. My suggestion is don’t use it while it will cause you trouble.
More information for you:
Single-Labeled Domain Names and Exchange 2007 SP1
http://technet.microsoft.com/en-us/library/cc788134(v=EXCHG.80).aspx
Microsoft Exchange compatibility with Single Label Domains, Disjointed Namespaces, and Discontiguous Namespaces
http://support.microsoft.com/kb/2269838
Help and support for namespaces in Microsoft products including Single Label Domains (SLDs), Disjoint Namespaces, and Discontiguous Namespaces.
http://support.microsoft.com/gp/gp_namespace_master#tab3
Providing Single-Label DNS Name Resolution
http://technet.microsoft.com/en-us/library/cc816610(v=WS.10).aspx
Regards,
Amy