RHN Satellite advice sought: Integrating EPEL and other repos

Hello All,

We're working on transitioning from a homegrown yum-repo based software management scheme to RHN Satellite as our central package management scheme. 

First some specifics on our environment:

• 1 Licensed RHN Satellite 5.4 on RHEL 6.2
• 300+ physical and virtualized Licensed RHEL 5 & 6 i386 & x86_64 clients
• Need to provide packages from: RedHat Main, EPEL 5, EPEL 6, Dell OpenManage, and in-house YUM repositories
• Each repo defined in RHN Satellite, with child channels defined under each main channel all pointing toward compatible repos.  Example:
  • Red Hat Enterprise Linux Server (v.6 for 64-bit x86_64) [official Red Hat channel]
    • EPEL 6 Server (x86_64) [custom defined child channel]
      • EPEL-6-REPO [custom repository definition]

Questions for the sages:

• Is this setup how others are managing EPEL repos on their RHN-managed RHEL clients?
• If so, are you finding you have to run a spacewalk-repo-sync action for each custom-defined child channel, even if they point at the same repos?
• How is everyone making this scale?  With each client only being able to subscribe to one Base Channel, and each child channel (like EPEL 6 x86_64) having to be defined once for each base channel that needs it, this is adding up to a ton of sync jobs. 
• Am I missing some fundamental way of making this scenerio more effecient with regard to repo syncs?

Thanks!