Would a guitar made of plutonium and nickel strings be playable ? Or would it blow up ?

dont know, but 30+ years ago walking by Sam Ash in NYC they had an 100% brass guitar in the window
with a sign that said ,"if you're into heaven metal try this guitar, it weighs 120 lbs!"

I was a teen at the time so my guitar playing skill wasn't honed yet and at the time I was only 25 lbs more than the guitar so I didn't try it

never seen anything like it since, btw- it was a strat style

Not much danger of it exploding. More danger to you being in contact with it, unless you wore a substantial lead vest.

I'm not an exotic guitar expert, but I'm coming up short when I try to imagine what advantage a plutonium/nickel guitar might offer.

It would rock !

:)

YEah def need a hazmat to play it, but meh, i cant imagine a plutonium guitar ...

It would be too soft, and poisonous to touch.
Would not stay in tune and sound dead.
A hollow steel or brass guitar imparts the ringing tone of the metal, the same as a acoustic imparts the woody sound.
A hollow plutonium guitar would be soft like a lead guitar and bend if thin enough to use, and be way too heavy if thick enough to be solid.

Thanks

Your nuts will fall off.