The point is whether the individuals report you and whether there is enough evidence of the griefing type behaviour being deliberate and focused - and like I said there is no hard and fast rule for what does and does not constitute griefing. The reporting system is only effective if people report the cases of genuine griefing - and no "griefing" does not require direct textual/voice communication.You can kill one player, and receive a warning if you make an offhand comment about the players supposed ethnicity.
Both griefing and combat logging are offences in the eyes of the EULA and TOS.
The comment thing is something else that is racism and covered by other things.
Whether your behaviour constitutes griefing is something only FD can fairly judge, to me it sounds like habitual ganking which while not explicitly griefing is in someways as bad if not worse - but I leave it up to FD how they want to deal with such behaviours. The new C&P system seems to be a start.