PSYN w/o Curse Client?

I'm trying to take pity on my Mac-using guildmates by throwing together a quick addon updating script which will run on the Mac. I had originally planned on only supporting WowAce, as their file structure is really simple, but I see they're actually publishing PSYN files for each of their addons now. Supporting PSYNs instead should allow my script to support both WowAce and Curse, but I'm having trouble accessing Curse's PSYN files, as it gives me a user/pass error.

So, regarding working with PSYNs,

• How do I specify user/pass? (I assume the user/pass in question is the user's Curse account.)
  
• Is there a DTD/schema available? The public DTD URL referenced from WowAce's files doesn't resolve to the DTD itself. (http://static.curse.com/psyn.dtd)
  
• Is there a way to get a specific PSYN only knowing an addon's name, rather than it's ID? Or a simple way to search addons programmatically?
  

Wait.. wowace has PSYN stuff live already? Oh wait.. you mean the psyn.xml file? I wouldn't use that right now.. it's for testing at the moment and it's not guaranteed to work in the future.

Bugger. Thanks for the heads-up, though.