Yeah I get it, my mom used to read the books to me and my sister when we were younger.
I think you're far enough that you should have discovered ancient magic (R1+L1 on PS5), which breaks shields, also if you hold down the protego/shield button so it activates stupefy when there's an incoming spell, that should work too, as will throwing objects at them.
So the story overall is the same, the friends are all the same, like the Slytherin character will still have the same affect on your game whether you're in Slytherin or Hufflepuff. Each house does have its own side quest towards the beginning of the game though. Some of them are better than others, but I'll let you look those up to spoil on your own if you're interested. But yeah the story being almost entirely the same is one disappointing aspect.
And yeah, no consequences for using the unforgiveable curses, which I kinda like, cause then you can just focus on having fun and playing the game without being evil and people treating you differently for it.
I will say too, there should be a talent tree unlocked at a certain point, which won't really change your playstyle much, but it adds a little extra flare to some of your abilities.