First of all,providing your skype username to other's is usually not an issue. But most people don't konw how,but providing your skype username is a simple way to get your IP address. Most people on Neopets related forums do not know how to do it.
To provide your skype from NOT getting hacked,first of course don't have simple passwords. Which could leave to bruteforcing.
Second,don't let people know who are on your contact lists. Don't know what kind of skype purchases they made,etc. Real simple stuff like that. Keep those details safe and to yourself only.
Most people don't make any skype purchases, so that's fairly simple, and if you're in a group chat with people, they've already figured out your contacts. And I did not have a simple password. All they had to do was pretend to be me by naming off the people in the Skype chat they were part of. You make it sound like it's hard to get hacked, and it's not, tons of people are part of group chats on skype and anyone could just have their crap taken.