I sent a PM about the bindings.
Leather are different than alpine boots. I actually want/need the fit to be better because I use my foot a lot more. Alpine is like a cast. If you can tolerate the pain, the tighter the better.
You want your leathers to fit pretty tight too. But also be able to move the way your foot will move. Most will and break into to your motion.
Things to be aware of are heel lift, arches being too tight or too loose, and toe box being too loose or too snug. These going one way or the other can lead to pain (blisters too loose or too stiff, cramps too tight - sometimes too loose) or just shitty skiing (too tight/stiff - no freedom, too loose - no control).
Best advice I can give you is you want these kind of boots to fit like a good hiking boot. It's essentially what you will be doing with some sliding involved - you want the sliding to be on the ski bases, not between your boot insole and the foot.
Just as example, I have custom inserts I use in my boots. I forgot to put them in once last year. I skied off, didn't really notice it on the flat terrain. First hill I was falling all over. Kept falling. Couldn't figure out why I couldn't ski. Got back to my car, took off my boots...

no insert. It felt really obvious when I knew it was missing.