SnuffleKitty,
when I am in your position in my forts, I use the silver to make silver warhammers, outfit my militia with bone armor, and set up cage traps for all invaders. Caged goblins get drowned, and then i harvest their goods, as that seems the safest way to get their stuff. You can then outfit your militia with goblin made stuff, or melt down their iron and copper items to do what you want--- like make bronze bars to turn into large bronze serrated discs (since you have the tin) for weapon traps to replace the cage traps near the entrance/invasion trapped paths.
Of course, your militia will upgrade from bone defenses to iron defenses. Haven't caught them moving to copper yet.
I prefer to rely on architecture to defend my fortress. As a consequence, I only need a militia to handle beserking dwarves, and bone armor is all they need for that. Bladed weapons end fights quickly, but hammers will get the job done no matter what it is they have to whack.
I have been intending to try turning silver into giant balls with spikes to see if the "giant ball" bit means it is a great "bludgeon" trap, or if it would be poor as the giant ball with spikes means it is a spike attack. If it is the latter, then I suppose 10 green glass giant balls with spikes would get the job done for traps, leaving me to save my iron bars for conversion to steel once flux is secured.