Here's a new solution for question 3a. This is not strict in the sense that you have to turn off strict for the set-up code to work. However, the actual test \$foo->[1] == \$foo->{1} runs under strict, unlike in my original symbolic ref solution.

I think that this solution differs from all the solutions given so far, so I submit it even though this puzzle is now quite old.

$R = "Regexp::"; *{"$R(\@{}"} = sub { &{sub{\@_}}(2,$t{1}) }; *{"$R(%{
+}"} = sub { \%t }; *{"$R()"} = sub {}; ${"${R}OVERLOAD"}{$(}--; our $
+foo = qr/a/; use strict; \$foo->[1] == \$foo->{1} or die;
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