This could be grouped under #47 but this isn't the same kind of issue totally.

Slabs are named as such slab/[height]/[type]/[material]
This doesn't match any other name system used. All other obtainable blocks are [baseItem]/[type]/[material]

I suggest the change to slab/[type]/[material] for slabs. Type can be either double_[type] or just [type]. This would shorten the name and remove the unneeded slab/half that exists. It's a slab, it's already expected to be half.