OK, I already have the BTC in an electrum wallet.
My question is, if I import the private key of the 1BTC addy to the "electroncash" BCC wallet is that all I need to do to move the BCC without fucking up my BTC?
You can
probably do this, but it means you have to completely trust electroncash. A much safer approach is to move your Bitcoin to a new address, one that isn't related to your old wallet, before importing your private key in any
untrusted software.
After this, you can import the private key to access your Bitcoin Cash. I don't trust Electron Cash on my normal computer though, so I used it in a VM (Virtual Machine) to be safe.
Next, you can do the same for Bitcoin Gold and Bitcore (I used Coinomi on Android to import those private keys).