There are reports of blurry text on monitors with resolutions around 1440p or less than UHD. macOS doesn't always scale fonts optimally on these, which can make coding feel straining over time. My recommendation is to look into a 4k or higher monitor for sharper text rendering on macOS, even on a smaller screen size.
That depends on the size. For 27" or larger, the recommened resolution is 1440p (non-retina) or 5K (retina). 4K is ok if you're going for smaller sizes.
