Yeah it's a pain. Although easy on Linux, shouldn't be too hard on a Mac (Fuse drivers are available). Although if I didn't have one of them I would just use another a Pi 2 with Ethernet.
A serial adapter is great if you have one. But for the average person who may have picked up their first Pi free with a magazine is highly unlikely to have one. For most people changing two files is a pretty quick, safe and easy way to get wireless networking going with minimal extra hardware. Although you could easily remount the SD card and view the log files if you needed.
Umm, but you can always remount the SD card on your computer or even reinstall the image. There is essentially no way to brick your device by doing this.
It sure will. It's a bit easier though as you can just use the ethernet port as that's already configured to use DHCP. So you can skip the step that envolves changing the files on the SD card.