I was gonna reply to this yesterday and I had a post all written down but then someone came over or something happened and I almost closed the browser on it now as well, so without further ado:
1. akacayman each LL is different. Some might list you the same day, some might take months.
2. If your hosting is down, it means that ALL the sites on your domain are offline, no? No matter when they were built or submitted. So it only makes sense they are all removed.
3. It also deppends on the reviewer, some might ask you WHY you sites are offline, some might not even delete them, just suspend them, some might delete all of the without warning... like with anything, if people know you and know you're alright, they might just give you a pass or be more lenient towards you.
If you ever have any problems with you hosting or something like that, always come on the board and post what the problem is, what is the affected domain(s) and how long will it take to fix. This will certainly help in not getting your sites deleted.
4. The principals? Not sure what you mean by that. Try reading link-o-rama's rules, if your site obeys those rules, you shouldn't have problems getting listed anywhere else:
http://www.link-o-rama.com/greenguy/therules.htm
Also, read this article:
http://www.hqpornlinks.com/webmasters/articles/LL.htm
The first thing you need to base yourself on is common sense. That, and try to think like a surfer. What would YOU like to see? How would YOU like it if someone tried to fuck with you? You get the point...
Best of luck!