6. Write a simple (common) regular expression to match an IP address, e-mail addr
+ess, city-state-zipcode combination.
You realise those regexes are neither simple nor common, but instead tend to be really fairly difficult, especially if you had to write one off the top of your head in a somewhat stressful situation, such as an interview.
As for the rest of your questions, what is the point of asking questions that could be answered in less than 10 seconds with access to perldoc? Are you just trying to quiz them on what knowledge they have memorized?
As for the rest of your questions, about what is suitable for perl, presumbably you're already doing a project in perl, and wish to hire someone to work on this project, so you know what perl is suitable for, because you've chosen it as a language already! What is the point of asking if he thinks it's suitable?