This is probably a stupid question, but I cant figure out what some of the hardware that came with the adjustable Konis are for.

Specifically the metal sleeves and the plastic washer.

I'm thinking that the metal sleeve is to be used as a spacer for the strut, and I was wondering if i could use that to gain suspension travel?

Search "Koni Sports for Classic Z's." This thread has all the information you desire and probably more, look at the latter pages of the thread.  

I have these on my car.

The silver metal spacer is a spacer for the shock and the top hat to the strut if I remember properly. It will not help gain suspension travel. It is just a necessary piece to make these shocks fit.

Black piece is the gland nut. Huge PITA if you don't have the right tool.

The knob adjusts the dampening.

TBH pretty sure I installed that plastic washer wrong. I used it on my dust bellow to protect the strut.