Are my retrieved BCCs stolen from my Electron Cash wallet?
I would not trust the Electron Cash software. Unless you experience one of the wrong server selected bugs, as other people describe in the linked questions, I would guess that the wallet sent your coins to someone elses address.

There is a warning about Electron Cash from Electrum:


  The person who distributes the Electron Cash binaries has decided to
  remain anonymous, and uses the fake name "Jonald Fyookball" in order
  to sign Electron Cash binaries. Thus, if these binaries contain code
  that is designed to steal your bitcoins, the author of the theft will
  be anonymous and walk away safely with your funds.