openzeppelin-contracts

Gasless is made possible by meta transactions, a proposal from last year: https://eips.ethereum.org/EIPS/eip-2771 For which Openzepplin proposes documentation and an implementation https://docs.openzeppelin.com/contracts/4.x/api/metatx https://github.com/OpenZeppelin/openzeppelin-contracts/tree/... Proxied versions of standard contracts are also proposed by Openzeppelin: https://docs.openzeppelin.com/upgrades-plugins/1.x/writing-u... https://github.com/OpenZeppelin/openzeppelin-contracts-upgra... For KYC you'll need to implement your own ERC20 compatible token with some checks in the transfer functions. The CMTA is the Swiss contract reference and proposes one: https://github.com/CMTA/CMTA20

Contract templates and libraries are being developed as part of OpenZeppelin: https://github.com/OpenZeppelin/zeppelin-solidity

I've been writing some smart contracts over the last couple weeks and have learned a lot from OpenZeppelin's solidity repo–you can either use them directly (importing and extending off of them) or use them as a good resource for building tokens, crowdsales, etc–can't recommend them enough. https://github.com/OpenZeppelin/zeppelin-solidity