The transaction with kinguin is safe. They even offer a cheap protection against non-working keys, so you are guaranteed to get a working key.
The big issue is the keys themselves aren’t always obtained legally. And then it can take a while for the key to get deactivated. By that point you are usually out of luck trying to get your money back or a new key.
Started playing yesterday, I can agree. I just need to get used to playing slower. It’s so easy to put it on speed three and then suddenly I am falling behind and can’t deal with the issues anymore.