You are probably safe from possible arrest. The worst that could happen to you is that your personal information will be taken by the authorities. The way I look at it, there is no reason why you should be punished along with the real criminals. I don't even think the money used by the criminals to buy BTC will get confiscated. They should focus on trying to confiscate the BTC instead.
We all know that bitcoin transactions can be tracked by the authorities because they are only stored in the bitcoin network.
So as you are not doing bad things and you're just making transactions then there's nothing to worry. You are not a criminal compared to those real criminal who are buying BTC illegally.
You are just selling BTC to anyone interested. You are not an investigator on the people you sold BTC to. Just like a money exchanger accepting clients without necessarily investigating whether they are going to use it for crimes or not. How would you know?
I forgot to mention that BTC itself is illegal in our country which is the major reason of my fear. I sometimes sold BTC to unknown guy and that's what I'm fearing of. If it was legal, I would have nothing to fear at all.
If that so, then that's a very risky move for you. You should be careful of selling BTC because authorities can use "someone" to find those people who are making bitcoin transactions. That's the reason why KYC is really important for most of us, especially for those people who are living in a country where cryptocurrency is illegal.