2. Two subscribers to one publication

I don't think it's a good question. A sequence would work, and use less space. There are issues with them, but I'd think that. The author was probably thinking guaranteed...

What's the error?

You can have proxies at a few levels, for agent jobs and xp_cmdshell. If nothing is set, the agent job should run as the Agent service account, not owner.

Central Management Server or Regate Multiscript can do this as well.

Have you tried backing up to a different location/drive/file?

AFAIK, you cannot convert the named instance to a default instance. You'd have to install as a default instance.

bump

I think the various suggestions posted are all likely good questions to think about writing about. If anyone wants to tackle any of them

This would be interesting. What Id' say is that you shoudl write about how you use this to help you, not try to solve every possible issue. You built these...

That's certainly what this is. There are customers that want this type of managed environment because of scale. They don't want to manage a data center any longer, or are...