So I have a large amount of Bitcoin I want to move to USD or another 'safe' fiat temporarily. Do people recommend the best ways to do this? What are liquid platforms that won't ask for my bank details etc.
If you want to temporarily store your bitcoins in fiat, then use Perfectmoney or Payeer. They won't ask you to furnish KYC at the first place. Just read through their FAQ and you will understand the upper limit. If you have a lot of money, then probably they will ask your KYC. However, if you keep below their limit, they may not ask.
However, I will suggest you to have a mixed bag. Keep some USD in your exchanges and cash out some to online payment wallets. But f you take the bank route, you will have to declare your identity.