I personally believe it's clear enough that I don't insist but would certainly like... one-character punctuation variables which are nice, too! ;) I fully second the rest of your suggestion, BTW.
If %- were not taken, I would have expected it to hold that kind of info. Methods would be the best thing though... I'm playing more and more with autobox but I know it doesn't fit too well in Perl 5's like typical mindset. (Apart the fact that its very docs warn about it not being real autoboxing!) And I don't know how would it square playing with such special variables as the ones we're discussing here...