Search for "FunkyScott" on youtube, he has a tutorial for themes and yes they are safe

Dont use theme manager it can cause bricks only use theme-manager for theme backups

join themecafe discord they got wonderful themes

use anemone, you can download it on universal updater.It's safe and i've downloaded multiple themes and it worked for me :D

I second Anemone!

i should have specified wii u