You are only getting the pseduo-hash warning because at one point you are creating an array reference whose first element is a hash, then later, treating that array as a hash, eg

$ perl588 -we'$h{a}[0]{b} = 1; $h{a}{x}{y}=2'
Pseudo-hashes are deprecated at -e line 1.
No such pseudo-hash field "x" at -e line 1.
$
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if you treat it consistently as an array you won't get the warning. Other than that, I don't really understand your question. All I can really say is that you can easily have an arbitrary heirarchy of arrays and hashes. This:

$galaxy{solarsystem}{planet}[year]{lat}{long}=’foo’;
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should just Do the Right Thing, as long as you don't later start doing {year}

Dave.