A few rear suspension questions

Unless you are trying to set records for a class I doubt you’ll notice the angled sliders.

The big deal is not getting any binding.

Edit: the front bolt is what moves the car. All forward motion goes through that bolt.

So its location both in height and front to rear location matters.

It’s hard with leaf springs to move the bolt reward in the car but you can. Up and down not only changes how the springs behave but it also changes ride height.