I have a few blood alloys and precious alloys. What can I do with these? I know that blood alloy can make the Forj Tempered Shield. Anything else?

there's a whole series of swords that are makeable at Genentech with stuff from the Sable Smithy. You can find the recipes by searching the notes section of Subetalodge's item search function. Blood Alloy and Precious Alloy are buyable from Mathis, but they can also be made.