A few ideas...
Tier 1 perks should unlock crafting tier 1 items, instead of tier 2 as it is currently. The current setup renders most tier 2 schematics worthless because it only costs 1 point to unlock the crafting. Maybe move the requirement up to tier 3 so there would be more of a skill point cost.
Add 1 more tier between stone and forged iron (perhaps scrap?) and one super tier that could only be crafted with its corresponding perk maxed out and no schematic existing (such as diamond-tipped).
Perking up in a specific weapon skill could raise y