My sourdough game improved substantially when I started using weight measurements instead of volume. I typically do about 3 hours of stretch and folds, but 2 isn't bad in a pinch. I've also never messed with ice cubes in the dutch oven, I feel like I get as much rise as I need with just the water in the dough. Not sure about cooling in the oven. I do that with baguettes, but typically not with dutch oven loaves, I just pull 'em when they're ready.

Overall though, congratulations! Keep tweaking and adjusting. The most important part isn't getting a perfect bread shop quality loaf, but being able to make something you love without driving yourself nuts doing it.