Optimal settings probably depend a lot on what you’re used to and which characters you like to play, particularly for choosing sensitivity curve. Linear is usually more intuitive for target tracking, but has less fine control for small changes at a given sensitivity setting than the “exponential” (it’s really quadratic, I’m 99% sure, x^2).
Lately I’ve been sitting on 69 sensitivity, I’ve variously used up to about 72 regularly. Widow and Ana have a higher than default zoom aim ratio, I don’t recall with certainty where I left it. Ashe I’m not sure what I did with her ratio if anything.
0 aim ease in, “exponential” curve.
100 aim assist, 0 window size, 100 aim assist ease in.
For projectile characters I sometimes cut the aim assist down to 90, so I don’t have to fight the assist as hard when leading shots.
Biggest thing is just going to be practicing something until you’re used to it; if you’re changing things a lot mid match or between matches to search for an “optimal” setting, odds are you’ll never quite settle into a comfortable groove.