I think you just didn't have the right settings for ABS. My experience is just the other way around, PLA parts are vastly inferior to ABS parts once you put in the effort to get ABS printing right. Even dirt cheap ABS (once dried correctly) outperforms PLA on all those aspects listed above.

As to acetone, the MAC value is still in the region of 800 ppm I think, which is orders of magnitude larger than non-body common substances. MAC is the maximum allowable concentration you can be exposed to for 40 hours per week during a whole life time without adverse effects. It is the by product of burning fat and is much more abundant in the body than the minute traces of formaldehyde.

A famous saying is that the toxicity is in the dose. 200 grams of common kitchen salt is also lethal. Breathing 100% oxygen is also lethal. Too much ethanol is also lethal. On the other hand the total absence of a lot of substances is also lethal (think iron, zinc, magnesium, etc). I did not say that you should liberally start drinking acetone, just that is a lot less harmful than the solvents you need to smooth PLA (which is actually possible).

I know you are a strong advocate of the premise that anything can be done with PLA, but for many people this is simply not the case.