When you say icons, do you mean the apps themselves, or just the layout, or the icons of the apps?
For the first, you can use Helium:
https://play.google.com/store/apps/details?id=com.koushikdutta.backup&hl=en From the CWM team, it's a non-root way to backup apps and app data. You do need a PC to back them up and restore them (which means you'll need to use either their Chrome app or their windows program), but it works without root. I've used this myself when I got my Galaxy S8, and it works great.
For the second, most launchers have this as a built-in feature, you could check there.
No idea on the third.