Ethereum NFT Marketplace Payment Integrations

We are building an NFT marketplace and we need the following integrations: 1. Buyer/Seller/Admin ability to connect third-party wallet(s) (multiple options needed for payment and/or holding the purchased collectible, including Metamask, Trustwallet, etc). Admin controls. 2. Buyer/Seller/Admin ability to create NATIVE wallet(s) (multiple options needed for payment and/or holding/offering the purchased collectible, including Metamask, Trustwallet, etc). Admin controls. 3. Buyer completes purchase with cryptocurrency (multiple options needed, including Bitcoin, Ether, Dogecoin) 4. Once purchase of NFT is completed and transaction has received adequate confirmations, three things must happen: a.) Fees (determined by admin) are paid to the platform's connected wallet, b.) Remainder of coins from sale (after platform fees) are paid to the Seller (Artist)'s connected wallet, c.) ERC721 token is then transferred to Buyer's collectibles wallet, or held in Buyer's native wallet on the exchange. d.) Automated invoice should be generated and sent to Buyer and Webmaster's via email once transaction is completed (this functionality is already built, but needs to be connected to crypto-based transaction). Additionally, the contract code for each NFT must be automatically retrieved and shown on NFT listing's front/back end. All tasks must be properly notated/comments before each subroutine, for easier auditing. These tasks must each be troubleshot, checked for any bugs AND security audited before individual task-milestones are released. Developer agrees to full refund, if ALL tasks cannot be fully completed. If there is a more efficient way to complete the above needed tasks, let's chat! Please let me know your thoughts, and I am happy to answer any other questions you may have. Thank you!