Só consigo lhe responder 2 das 4:
- Recuperar Produtos de um "Product Cluster"
https://documenter.getpostman.com/view/845/vtex-search-api/Hs43#e0ec3923-faf7-5049-8634-f6d617ce5f67
Filter by colection
- Gerar o carrinho / checkout com as infos da lista.
https://github.com/vtex/vtex.js/tree/master/docs/checkout#addtocartitems-expectedorderformsections-saleschannel