• 2. several my ($var1,$var2,%hash1); lines is ok.
  Learn to use hash/array to reduce the number of variables and group them in useful structure.
• 3. Super Search my frien, Super Search is your friend.
  Almost all is said in my and local??.
  In brief lexically scoped variables are a kind of local variables.

As Jepri said you'll probably have to play with Objects,
as he already suggested perlboot, I will only add perltoot and Object Oriented Perl
(I haven't read it yet but I've only heard good comment about it...)

"Only Bad Coders Code Badly In Perl" (OBC2BIP)