Yeah, they're fine, just make sure you use all the PPE as @umop3pisdn says. Also, use thin discs, they're way better than the chunky things that come with the grinder. Cut only, use something thicker or ideally a flapwheel if you want need to deburr.
Was thinking of going for a diamond disc as they are made of steel, so presumably less likely to break up and decapitate me (as in the various photos).
I've been using that style of disc to cut steel for ten years, never had one explode on me. I have, however, had a bit of steel in my eye. Do wear specs.
Yeah, they're fine, just make sure you use all the PPE as @umop3pisdn says. Also, use thin discs, they're way better than the chunky things that come with the grinder. Cut only, use something thicker or ideally a flapwheel if you want need to deburr.