|XP is just a number|
Your list is nothing more than yet-another-arbitrary-and-capricious-ruleset that uses thin justifictions to imbibe your personal preferences with theocratic status. Yet another list that doesn't correspond with anyone elses arbitrary list. Another set of arbitrary rules that will confuse newbies and frustrate the experienced coming from other places where different arbitrary lists were in force.
There is only one definitive list -- it's called Perl.
You are second guessing the heralded and qualified language designer to come up with some subset of the defined language on the basis of what qualification?
Even where you agree with the language designer in one place -- lower-case and underscores -- you later contradict him -- and yourself -- with "only CamelCase". This is both capricious, and more damning, inconsistent.
Your rules appear to be aimed to favour restricting and emphasising the linguistic elements of the language, rather than the structure of the algorithm, which is the completely wrong thing to be doing. The language's syntax is already very constrained and well documented. Whether those completely new to programming, or those migrating in from other languages, learning Perl syntax is just a matter of exposure.
What all programmers should be doing when writing their code, is trying to capture the essence of the variable part of their programs -- the algorithms -- in as clear and concise manner as possible. And perl's full syntactic richness is expressly designed to allow that to be done.
By placing arbitrary restrictions on that syntactic richness, you do not make it easier to read the code, because the inevitable affect is to force the programmer to use more verbose code to capture the essence of the important part of the source code -- the algorithms.
See also Re: What is code readability? and follow-on discussion for specific counter example to some of your justifictions.
With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.