Dude, yeah! I was wondering the same thing - I'm here from Sydney, would love to catch up with Ubuntu lovers while I'm here. :-)

I'm new in ubuntu but I will try to answer your questions. (sorry for my bad english)

> * How do I rollback patches that come out for Ubuntu?
I think: apt-get remove

> * When should I reboot after applying a patch?
You soudn't reboot normaly if you don't change your kernel

> * When it comes time to upgrade to Breezy, how will I do it, and how will I ensure that my system doesn't blow up?

> # Startup scripts: what is the chkconfig equivalent on Debian/Ubuntu?
man update-rc.d

># Documentation: aside from Ubuntu Guide, what other definitive documentation repositories exist? Is there anything like the FreeBSD Handbook?
There are a lot like this:
---
cd /etc/apt/ && mv sources.list sources.list.orig && $/usr/bin/wget http://download.ubuntuforums.org/ubuntusetup/sources.list%20%20%20%20*%20How%20do%20I%20rollback%20patches%20that%20come%20out%20for%20Ubuntu?%20%20%20%20*%20When%20should%20I%20reboot%20after%20applying%20a%20patch?%20%20%20%20*%20When%20it%20comes%20time%20to%20upgrade%20to%20Breezy,%20how%20will%20I%20do%20it,%20and%20how%20will%20I%20ensure%20that%20my%20system%20doesn't%20blow%20up?%20http://download.ubuntuforums.org/ubuntusetup/sources.list
gpg --keyserver wwwkeys.eu.pgp.net --recv-keys 1F41B907
gpg --armor --export 1F41B907 | sudo apt-key add -
---

># Where is the best place to go with Ubuntu questions?
I think it's in ubuntu's forums.