RE: Top layer, unsightly
That is the nature of 3d printing. That is called stair stepping and is the result of the object being rendered into printable layers. The shallower a slope the more pronounced it becomes.
The only things you can do are either use a smaller layer height, which is where the variable layer height tool becomes useful, but also has its own drawbacks, or you find a better orientation for the part so you don't have shallow angles. Obviously this is entirely dependent on your objects shape as to if that is possible or not.
Absent that you do what everyone else does and post process your prints, ie sand and fill if you want perfectly smooth surfaces. Or you go to a resin printer that can do much thinner layer heights. Even there though the effect still exists its just less.
RE: Top layer, unsightly
https://help.prusa3d.com/article/variable-layer-height-function_1750 this helps a bit
See my GitHub and printables.com for some 3d stuff that you may like.

