Thanks for the reply! I guess you mean the thread "Using Armory on the BCH chain"?
I've read the first couple of posts, but since I'm a complete newbie I didn't really understand that much (will read it again though). Is it completely safe (i.e. is there a slight chance that I fuck up and somehow lose my regular BTC?)?
That'd be the thread, but you should also read up elsewhere online about how it works, and the differences between BCH and BTC.
Should be "safe" as long as you use Armory to split and
make sure you sign with the BCH signer. Do not expose your private keys.