Pre 1982 pennies have 2.5c of copper (vs 0.7c of zinc in modern pennies) but it's not worth sorting through change unless you have a massive volume and a weighing machine to sort them for you

I consider all the counterfeit coins trash - quarters, pennies, dimes, half dollar, dollar are all base tokens and even then they have a cheaper core that's plated or sandwiched by a shinier/ more valuable material. Only good for spending as currency, just like paper fiat

Nickels are 75% copper 25% nickel solid alloy and are worth over 6c, so if/when gold & silver availability dries up you might still be able to withdraw nickels and come out OK, at least for small balances. Should be good for barter, albeit bulky