Hi Limo, this isn't an answer to your question here, but I'd like to recommend the Perl Cookbook to you. You're starting to move beyond some of the basics, and I think you would benefit a lot from this book, especially if you learn by example. I've been using Perl for years prior to getting ahold of this book, and it has dozens of tips and interesting Perl tidbits and shortcuts that will make your life a lot easier. A lot of the scenarios it covers are similar in scope and level of difficulty to some of your questions.
Good luck.