I second the notion of using discord. As I have said before - the admin crew could easily set up an official, FREE, discord server (it supports up to 1000 users!). It has voice channels, text channels with chatlog, private messages, friendslist and everything else you might need.
If the admins do not feel like setting it up I'd volunteer to set up the usergroups and channel permissions. But discord is by far the best option out there at this point. You can open it in your browser or get the desktop application (then it supports push-to-talk). Free and easy to maintain. You can even have bots for it if you wanted - there's a huge amount available.
Skype is cancer and needs to be treated.
Edit: Oh, and it also has server-wide announcements and pinned topics! Perfect to let newbies know where to look for help!