Just drawing lines, at some rotations they appear very blurry and pixelated. Is there anything I can do to make them sharper?
Example here:
https://editor.p5js.org/GaryHomewood/sketches/hBDmOiOHq
Using fractional stroke width (i.e. 1.5) can definitely contribute to blurriness. Otherwise this is just anti-aliasing and that cannot be turned off in 2d mode (see this question on StackOverflow).