My first sourdough baguette

Ok, I did my first attempt at sourdough baguettes.

flour (shipton mill french 55) 378g
khorosan (shipton mill) 50g
water 292g
salt 10.2g
sourdough starter 168g

No autolyse
4 coil folds, 30 min apart
3h bulk @25.5C internal temp
Preshape, 15 min, shape
1hr fermentation
15 min @250C with steam
12 min @225C without steam

Now, for the questions.
1. Crumb structure is a bit more dense then I expected. Would overnight fridge ferment aid that?
2. I followed a recipe from king arthur’s youtube to a decimal of a gram, but the dough was much stiffer then I’m used to in 75% sourdoughs, maybe that also contributes to crumb structure being full of small bubbles, instead of even medium ones?
3. It cracked from beneath. I have used the fancy sourdough thingy-shape instead of the stone. Or is it more about initial temp being too high and humidity too low?

What would you change?
Thanks!