Sane resizing options
The most common user behaviour when using desktop messengers is to snap them to the side/corner of the screen and make the user list as thin as possible to allow people to keep the user list permanently on top but not take up too much desktop space.
Right now if you resize the window as thin as possible it's over double the width of the steam messenger. There's simply no need to waste peoples desktop space, most of that area is just white space inside the user list, totally arbitrary restriction that needs to be removed. If you must have a min width then make it 50% thinner, or use the Steam messenger as reference.
Can you also fire the person who made the decision to attach text chat to the user list and restrict us to speaking to 1 person at a time. I know this is already requested and in the pipeline but it's legitimately the dumbest design decision I've ever seen in any product, ever and forcing that onto millions of users shouldn't be a thing you can do and keep your job. Thanks.
John S Wolter commented
....and adding to this maybe a bar that rests on the sides, top, bottom, or active icon that expands out Skype when a mouse or stylus hovers over them. 2nd put Skype to low priority sleep until activated by an incoming alert or user actions to use Skype in some way. PS: the addressbook sucks.