Hi Michele,
In all Framework based skins you will find a folder called "includes". Immediately inside this folder is a file called "administration-drawer.html", which is added to the layout.Master with an #include tag.
There are a few options for getting the results you're after, one is to restrict the view of the admin bar to certain roles. To do this you can wrap all the markup in that .html file with something like this:
<% if (WebUser.IsInRoles("Admins,Adminbar Enabled Role")) {%>
<!-- Admin bar code here -->
<% }
The "IsInRoles" method accepts a comma-separated list of role names. There are a few script tags at the bottom of the file which already use this method to restrict the rendering of a variable that is passed to a JS script in the skin based on role, this variable only controls the initial visibility of the admin bar though. If you take this approach I recommend you simply move the <% if () {}%> statement from line 73 up to line 1 and then adjust the roles you'd like the bar to be visible to.
Another approach to this would be to wrap just the member list link with this role-check code, which would look something like this:
<% if (WebUser.IsInRoles("Admins,Memberlist Enabled Role")) {%>
<li><portal:MemberListLink runat="server" /></li>
<% } %>
Note: The MemberListLink is on line 58 of the administration-drawer.html file in framework unless you've already edited the file.
I hope this helps!