All actions using singleclick - no doubleclicks, please? ;)

I didn't found (did I miss somenthing?) a way to have all possible actions available with just single click - to avoid double clicking - is it possible?

If not - perhaps it could be implemented (as new option)? It's much more comfortable, than double-clicking. F.e. it doesn't have any substantiation to me, why it takes double-click to expand chatroom-list instead of just "one and only", single click...