++ for your post.
These are my 0.02€ to your rule1. I am very much a fan of using modules, which make the simple things even simpler, e.g. the List::* modules.

• List::Util
• List::MoreUtils
• List::Pairwise

However modules should not be chosen, just because the name smells right. In the end you can shoot yourself in the knee, e.g. use File::Copy to copy executable files and end up with permissions reset to default ( see http://abigail1.hates- software.com/2005/09/21/0692681a.html).