EDIT: FEISTY ALICE POINTED OUT: ACETONE CAN RUIN PAINTED REO FINISHES! I ONLY USED IT ON RAW ALUMINUM! PLUS, IT'S NASTY SH_T. . . . . . . . .(SHE SAID . . . . NO, REALLY). ACETONE IS HARMFUL IF INHALED, SKIN CONTACT, ETC.!!!!!!

I had to really clean up my potty mouth when I attended Baylor. I now only use four letter words every few sentences when among friends.
But seriously, acetone is no worse than a lot of chemicals peeps use, frequently carelessly, around their homes. Stay away from flames and have adequate ventilation. Good to use gloves. Dispose of used "rags", just like with any flammables/combustibles, into outside containers where fluids will evaporate via air. Some "plastics" can handle short term exposure to acetone but not long term.
I'm used to handling a lot of stuff that scares peeps if they aren't familiar or educated on its use. So are most peeps, using stuff around the home and not aware of potential dangers. Big problems come when things are used with inadequate knowledge of uses and/or precautions to take when using.
One very common thing a lot of peeps don't know, for instance, is don't
throw water on grease fire. Don't mix bleach and ammonia. This one I've done only once and I did know of the potential but was in a hurry..... Don't open a container that might have chlorine gas in it with face close to container.
{edit} Just thought of this one. When you open or use muriatic acid (a dilute form of hydrochloric acid) the fumes seek human faces no matter the way the wind is blowing.

(a little exaggeration here, of course)