Which filter artifacts can be eliminated without trade-off?, (in a universe where computing power comes free) Options

[googlebot]

I'm learning, please correct any of the following sentences, if the aren't correct:

1. We cannot eliminate ringing, just choose where we want it (pre-, post-).
2. We can minimize ripple by computing power (choice of windowing function) without quality trade-off.
3. Aliasing in resamplers can eventually only be controlled by passband width and filter steepness (dependency to 1).

If 3 is true, why does the SoX offer a dedicated "allow aliasing" option besides bandwidth and steepness?