My community currently only distinguishes between "Guests" and "Members."  I do not have a "Validating" primary group. Is that a normal thing to have?  How do the rest of you setup your primary user groups for new members? I want to ensure only validated emails are able to post and comment, etc. 

If you don’t allow guests to post and registration requires validation, then you get what you want. No need for a validating group. A user who registered, but isn’t validated, won’t have member permissions in this case.