I think that many of the categories you have listed above have little to do with someone's Perl or any programming ability. If anyone tracked the "ability" of a programmer by any of the above, I would suggest intense therapy and shock treatment. Programming skills can usually be seen in the little things. We did technical interviews for C programmers a while the very bad programmers weeded themselves out quickly, the little things showed us who the good programmers were. Some of the things we looked for were:
- No syntax errors on whiteboard coding. The great programmers rarely had one.
- Immediately wrote down a closing curly ("}") after opening a block. They often had to erase as they went on, but it gave an interesting glimpse into their thought processes.
- Had a very strong editor preference. We didn't care if they prefered emacs or vi, we just cared that there was a preference. Some even expressed preferences by operating system.
- Used the (0 == foo) style syntax in conditionals. These people had been
burned by an assignment in a conditional and learned from their mistakes.
The little things quickly separated the adequate programmers from the good and great programmers. Several articles have been written in the past regarding similar traits of good programmers. There is one caution though. Good traits in one programming language do not necessarily translate to other programming languages. Be careful to define the little things appropriately for the language you have questions about.