I know meteor kind of compiles the templates up down to the client. With the meteor-auth system is there a way of only sending down templates when the user has permissions to se
I don't believe that this is possible, yet.
For an Admin section, you could create two separate apps and have them communicate through the same DDP server. This would make sharing code more difficult, however.
DDP can work with any database, framework, or programming language, and it can work on servers, clients, and mobile devices. In fact, you can call Meteor.connect to connect to any DDP server -- such as a Meteor app written by someone else! -- and make realtime subscriptions to any data it's publishing.
http://meteor.com/blog/2012/03/21/introducing-ddp