Some questions regarding the resistors and capacitors around an opamp
Main effect of that loss of sharpness is to delay the sliced output pulse. Whether or not that's a problem depends on context we don't have.
Secondary effect, IF the waveform doesn't reach its steady state value before the next edge, is to change the observed duty cycle. Again, we don't have the context to know if that matters. You'll observe this at about 3-4x the signal frequency you're using now.
Ultimately, as you increase frequency, the signal won't reach the slicing point and will disappear altogether, which is a problem if it occurs at frequencies of interest.
You can mitigate these by reducing the R-C time constant if necessary.
Increase the resistances too far and op-amp input bias and offset currents start to matter, and so do stray capacitances including the opamp input capacitances. These currents and capacitances will be in the IC's datasheet.
Use Ohm's Law and calculate R-C time constants to decide for yourself if you can increase these resistances without compromising accuracy or performance.
The idea is that when the output switches, the positive feedback capacitor C1 should give a big enough kick to the input to cross the hysteresis. Otherwise there's a time window when input noise can still cause glitches as C2 charges to the new limit via R1. Do the math, (note R2 = 34k of course) and you'll see C1 is too small.