If I'm using Perl 5.16 why do I have to type: use 5.016; at the top of every script?

You posted this exact same question back in 2011, in Why version strings?, and got a ton of replies.

Your suggestion for use no my; already exists and is called no strict 'vars'; - unless you can explain exactly how your proposal differs from the latter?

If you don't like boilerplate, program some Java for a while and then come back to Perl ;-)