Cables / Connectors

I’ve read that pro gear should use balanced connections, but I’ve been looking for a mixer recently and find that most have unbalanced insert points. My interface uses balanced I/O, as does most of my outboard gear. What gives?

I have three laptops in the house, all of which produce various sparks and flashes at the mains end when plugged into the wall. Can this be ‘right’ ?

If you’re choosing a new audio interface or a new computer, what are the pros and cons of the many different connection protocols that are on offer?