Complex sentence: It provides an opportunity for skeptics and rationalists to talk, share ideas in a casual, relaxed atmosphere, and discuss whatever topical issues come to mind, as well as having fun while promoting skepticism, science, and rationality.
Split into simpler sentences: It provides an opportunity for skeptics and rationalists to talk, share ideas in a casual atmosphere, and discuss whatever topical issues come to mind. It allows participants to have fun while promoting skepticism, science, and rationality.