WRT to your item 5: If you're doing anything serious with Perl you DO NOT want to use the OS' perl as that way lies much pain. Doing so couples you tightly to the OS' upgrade schedule for both the language and (if you're using its package manager for them) CPAN modules. If you're in some sort of (e.g.) shared hosting environment where you don't have tight control over the OS and what's installed it's probably just a matter of time until something "upgrades" underneath you and you're stuck either pleading for a rollback or trying to patch your code to work around some issue. (edit Even if you do have some degree of control you can still shoot yourself when you find your OS upgrade installed a breaking change; speaking from experience here as I learned this principle the hard way . . .)

You should always whip up your own "application perl" (by hand or with perlbrew) and use that to run your code and probably even use something like local::lib or Carton to maintain your CPAN dependencies.

(Granted if your "OS'" perl is from a container context you could prossibly relax this requirement because you're in effect baking up your own controlled "separate" perl install; that's a bit different in the details but similar in spirit.)