I am a huge Nirvana fan. Kurt liked medical books, liberal politics, and was really into underground music. He was a big proponent of gay and women's rights. Despite conspiracy theories, he really, really loved Courtney.
He didn't care about looks or fashion which is why he wore the clothes he did. He loved goddess symbolism and you can see the Goddess symbols on the back of In Utero. He had things such as the double axe. Bees, the ocean, and the moon are use. You could probably do a basic Wiccan set up for him. He focuses on the element of water, mostly the ocean, the is because he is a Pisces so symbols and dreams relate to a lot of it. (Any Pisces symbolism would work.)
(In fact you could probably worship the Goddess along side of him because he loves women so much!)
He hates rapists a lot so doing justice spells on them would make him happy. He loved the concept of justice.
Here is a symbol guide: http://camia321.tripod.com/nirvana/id21.html
He was fond of flowers, especially poppy which you can probably use fakes for.
There is saint candles for him: https://www.etsy.com/listing/269132542/ ... uwEALw_wcB
I know a lot about him so hit me up for any information.