excess acetone inhalation causes anosmia - loss of the sense of smell, which also means you can't taste anything.
Not trivial.
I never heard of that one, do you have a link for me?

Acetone also causes headaches - so regardless of whether or not it;'s a naturally occuring substance - it's not good stuff to be breathing in constantly.
So does alcohol and any load of other volatiles.

It's also highly combustible.
As are organic solvent based paints, lighter fuels, cleaning spirits, rubbing alcohol, paint thinner, glue removers, etc etc.

Just not good stuff to have in an enclosed office or workshop.
As with all of the above, always use in a well ventilated area (as the packaging also will advise). My sole point is that acetone is much less harmfull than for example paint thinner or glue remover and it will not poison you. Toxicity is in the dose (an oral dose of 200 grams of table salt will kill you) and it is very very hard to get anywhere near harmful levels with acetone. Just use it as advised (in a well ventilated area). By the way, nail polish remover is 98-99% acetone with some additives to make it smell different (I won't say nicer) and add sometimes add extra oil for the nails. And that product is usually applied in poorly ventilated environments.....