Don't think name changes are ever alowed under normal circumstances, though obvious spelling mistakes are sometimes. I've heard, this prevents agencies from buying a bunch of tickets under pseudonyms at the cheapest fares then reselling them for profit after the cheaper fare buckets sell out.

On a full fare ticket there's no need for a name change. You cancel the reservation then use the value toward the new ticket. That is a 1:1 swap in many cases unless it was a sale or mistake fare that has risen since. No need to refund first.

Having said that, there are some countries where names are not checked against tickets/boarding passes on domestic flights, so you could in theory use someone else's tickets in those places.