It's pretty good but I recommend settings the number of points above 60k because otherwise the coasts look pretty bland.
Yep, but at least there are plenty of settings to fiddle with. I've stuck it at 20k for experiments or scribbles, but when I start working on a serious setting I'll dial it up.
Calculating climate zones is time consuming, but it turns out a computer can do it pretty quickly these days. The river and lake generator is fine, we just need to draw in any lakes above sea level for ourselves.
The states and cultures and religions generator can throw up some interesting mixes, like maybe capital city is one culture, but the state is mostly another, while the religion comes from outside the region, suggesting a whole swathe of history that you could embellish.
Also - I would play the heck out of a civilization type game that used this to generate the maps. It doesn't even look too difficult to code something like Civilization or Imperialism or even a paradox-a-like into it, now that someone has already done the hard parts ; ) I myself lack the coding skills to do it, but it's not an impossible project for someone who is learning.